This is a working overview of gelatin, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-02 and is reviewed periodically as new material appears.
Quality control for collagen peptides includes measurements of moisture content, ash, protein content, and heavy metals. Microbial limits are set to ensure food or cosmetic grade safety, and the degree of hydrolysis serves as a key process indicator. That indicator correlates with molecular weight distribution and solubility characteristics. Regulatory requirements vary by country, and some jurisdictions restrict label claims about health effects. Documentation such as certificates of analysis and safety data sheets typically accompanies commercial shipments of the material.
Analytical testing of collagen peptides focuses on identity, purity, and molecular weight profile. Size-exclusion chromatography separates peptides by hydrodynamic volume and is often calibrated with known protein standards. Amino acid analysis after acid hydrolysis provides the compositional profile, which can confirm the collagen origin. Mass spectrometry offers detailed sequence information for individual peptides. These methods together help ensure that a product matches its specification and that batch-to-batch variability is controlled.
Common sources for collagen peptide production include bovine hide, porcine skin, fish skin, and poultry cartilage. The raw material is first cleaned and then treated with enzymes such as pepsin or microbial proteases under controlled conditions. Hydrolysis time, temperature, and enzyme concentration influence the final peptide size distribution. After hydrolysis, the mixture undergoes filtration, purification, and drying to yield a powder. The amino acid composition is notable for high levels of glycine, proline, and hydroxyproline, which are characteristic of collagen.
The functional properties of collagen peptides depend on their molecular weight profile and amino acid sequence. They are highly soluble in water and produce low-viscosity solutions even at relatively high concentrations. Some peptides exhibit surface activity, which allows them to act as emulsifiers or foaming agents in food systems. The absence of a rigid triple-helical structure distinguishes them from gelatin, which can form gels upon cooling. Chromatographic separation and mass analysis are used to characterize the peptide mixture.
Collagen peptides are short chains of amino acids derived from collagen, a structural protein found in connective tissues such as skin, bone, and cartilage. The production process involves breaking native collagen into smaller fragments through hydrolysis, which cleaves peptide bonds. Unlike intact collagen, these peptides dissolve in water and do not form a triple helix. Commercial preparations typically contain peptides with molecular weights ranging from about 2,000 to 20,000 daltons. The term collagen peptide is often used interchangeably with hydrolyzed collagen or collagen hydrolysate.
| Property | Value | Notes |
|---|---|---|
| Molecular weight method | Size-exclusion chromatography | Calibrated with known standards |
| Moisture content | ≤ 10% | Typical specification for dry powder |
| pH (1% solution) | 4.5–7.0 | Depends on source and process |
| Microbial limit | < 10,000 CFU/g | Common specification for food-grade material |
| Heavy metals | < 5 ppm (lead) | Regulatory limits vary by region |
Quality control of collagen peptides relies on methods that characterize molecular weight distribution, amino acid composition, and purity. Size exclusion chromatography (SEC) is commonly used to estimate the molecular weight profile of peptide mixtures. High-performance liquid chromatography (HPLC) can separate and quantify individual peptide fractions. Mass spectrometry provides detailed information on peptide sequences and modifications. These techniques help verify that a product meets declared specifications, though standardization across laboratories remains limited.
Additional tests assess moisture, ash, and nitrogen content to confirm overall composition and processing consistency. Heavy metal analysis, including lead, arsenic, cadmium, and mercury, is performed to ensure limits are not exceeded. Microbial testing checks for total aerobic counts, yeast, mold, and specific pathogens such as Salmonella and Escherichia coli. These safety parameters are often required by regulations for food or dietary supplement ingredients. Results are compared against internal or pharmacopeial specifications, which may differ between jurisdictions.
Collagen is a structural protein found in connective tissues of animals, and collagen peptides are short amino acid chains produced by hydrolyzing native collagen into smaller fragments. The hydrolysis process typically uses enzymes or acids under controlled conditions. Commercial collagen peptides often come from bovine hide, porcine skin, or fish scales. The resulting material is water-soluble and differs from intact collagen in molecular size and behavior. The term 'collagen peptide' generally refers to a mixture of peptide chains rather than a single defined molecule.
Production begins with cleaning and mincing raw collagen-rich tissues. The material undergoes pretreatment to remove non-collagenous components, followed by hydrolysis using enzymes such as pepsin or alcalase, or by acid or alkaline treatment. Reaction time, temperature, and pH influence the average molecular weight of the resulting peptides. After hydrolysis, the mixture is filtered, concentrated, and dried, often by spray drying. The final product is a powder with a characteristic amino acid profile rich in glycine, proline, and hydroxyproline.
Collagen peptides are distinguished from gelatin by their lower average molecular weight and better solubility in cold water. Gelatin forms gels upon cooling, while collagen peptides typically do not. Molecular weight distributions for commercial collagen peptides often range from about 2 to 20 kilodaltons, though exact profiles vary by manufacturer and process. Products may be sold as powders, capsules, or liquids. The term "collagen hydrolysate" is frequently used as a synonym, although labeling conventions differ across regions.
Analytical methods for collagen peptides focus on molecular weight distribution, amino acid composition, and purity. Size exclusion chromatography with UV detection is widely used to estimate molecular weight ranges. High-performance liquid chromatography can quantify hydroxyproline after acid hydrolysis. Mass spectrometry provides detailed sequence information for individual peptides. Other tests include moisture content, ash, heavy metals, and microbial limits. The choice of method depends on the specific quality attribute and the required sensitivity.
Storage and handling of collagen peptides require protection from moisture, heat, and light. The powders are hygroscopic and can absorb water from the air, leading to clumping or microbial growth. Typical storage conditions are a cool, dry place at room temperature or below, in tightly sealed containers. Some manufacturers recommend refrigeration for long-term stability. Solutions prepared from the powder are less stable and should be used promptly or preserved according to validated protocols.
=== Next generation PEGylation === Chilkoti's research group has developed next-generation polyethylene glycol (PEG)-like conjugates that overcome the immunogenicity issues associated with traditional PEGylation. PEGylation—the attachment of polyethylene glycol (PEG) to biologics—is commonly used to increase their half-life or reduce their immunogenicity, but PEG has itself proven to be antigenic and can elicit a serious anaphylactic response. To overcome these limitations, he designed a new PEG-like stealth hyperbranched polymer that breaks up the long antigenic ethylene glycol sequence in PEG and presents them as much shorter side-chains along a polymer backbone. Peptides and proteins conjugated to this next-generation PEG-like polymer show even longer circulation than PEG conjugates, do not bind to pre-existing anti-PEG antibodies that most people have developed, and do not generate an immune response to this new polymer. He has demonstrated the utility of this technology with a peptide drug for type 2 diabetes, an enzyme drug used to treat gout and an aptamer drug.
=== Design and control === Despite the dynamic nature and lack of binding specificity that govern the formation of biomolecular condensates, synthetic condensates can still be engineered to exhibit different behaviors. One popular way to conceptualize condensate interactions and aid in design is through the "sticker-spacer" framework. Multivalent interaction sites, or "stickers", are separated by "spacers", which provide the conformational flexibility and physically separate individual interaction modules from one another. Proteins regions identified as 'stickers' usually consist of Intrinsically Disordered Regions (IDRs) that act as "sticky" biopolymers via short patches of interacting residues patterned along their unstructured chain, which collectively promote LLPS. Another class is RNA-based design demonstrated as TEARS (Transcriptionally Engineered Addressable RNA Solvent droplets), where repeating CAG ribonucleotides (rCAG) function as the multivalent "stickers." to form condensates within bacterial cells. By modifying the sticker-spacer framework, i.e. the polypeptide and RNA sequences as well as their mixture compositions, the material properties (viscous and elastic regimes) of condensates can be tuned to design novel condensates. Other tools outside of tuning the sticker-spacer framework can be used to give new functionality and to allow for high temporal and spatial control over synthetic condensates.
== ISO 3650 – ISO 3999 == ISO 3650:1998 Geometrical Product Specifications (GPS) – Length standards – Gauge blocks ISO 3651 Determination of resistance to intergranular corrosion of stainless steels ISO 3651-1:1998 Austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in nitric acid medium by measurement of loss in mass (Huey test) ISO 3651-2:1998 Ferritic, austenitic and ferritic-austenitic (duplex) stainless steels — Corrosion test in media containing sulfuric acid ISO 3651-3:2017 Determination of resistance to intergranular corrosion of stainless steels — Part 3: Corrosion test for low-Cr ferritic stainless steels ISO 3652:1975 Shipbuilding — Inland vessels — Rope reels [Withdrawn without replacement] ISO 3653:1978 Cinematography — Spindles for 8 mm Type S motion-picture projector reels/spools — Dimensions ISO 3654:1983 Cinematography — Motion-picture camera cartridge, 8-mm Type S, Model I — Cartridge-camera interface and take-up core drive — Dimensions and specifications [Withdrawn without replacement] ISO 3655:1986 Acceptance conditions for vertical turning and boring lathes with one or two columns and a single fixed or movable table — General introduction and testing of the accuracy ISO 3656:2011 Animal and vegetable fats and oils — Determination of ultraviolet absorbance expressed as specific UV extinction ISO 3657:2020 Animal and vegetable fats and oils — Determination of saponification value ISO 3658 Crude or liquid petroleum products — Determination of density and relative density — Graduated bicapillary pyknometer method [Draft merged into ISO 3838] ISO 3659:1977 Fruits and vegetables — Ripening after cold storage ISO 3660:1976 Fishing nets – Mounting and joining of netting – Terms and illustrations ISO 3661:1977 End-suction centrifugal pumps — Baseplate and installation dimensions ISO 3662:1976 Hydraulic fluid power — Pumps and motors — Geometric displacements ISO 3663:1976 Polyethylene (PE) pressure pipes and fittings, metric series — Dimensions of flanges ISO 3664:2009 Graphic technology and photography — Viewing conditions ISO 3665:2011 Photography — Intra-oral dental radiographic film and film packets — Manufacturer specifications ISO/TR 3666:1998 Viscosity of water ISO 3667 Aircraft — Dimensions of hermetically sealed contactors [Rejected draft] ISO 3668:2017 Paints and varnishes — Visual comparison of colour of paints ISO 3669:2020 Vacuum technology — Dimensions of knife-edge flanges ISO 3670:1979 Blanks for plug gauges and handles (taper lock and trilock) and ring gauges — Design and general dimensions [Withdrawn without replacement] ISO 3671:1976 Plastics — Aminoplastic moulding materials — Determination of volatile matter ISO 3672 Plastics — Unsaturated-polyester resins (UP-R) ISO 3672-1:2000 Part 1: Designation system ISO 3672-2:2000 Part 2: Preparation of test specimens and determination of properties ISO 3673 Plastics — Epoxy resins ISO 3673-1:1996 Part 1: Designation ISO 3673-2:2012 Part 2: Preparation of test specimens and determination of properties of crosslinked epoxy resins ISO 3674:1976 Shipbuilding — Inland vessels — Deck rail [Withdrawn without replacement] ISO 3675:1998 Crude petroleum and liquid petroleum products — Laboratory determination of density — Hydrometer method ISO 3676:2012 Packaging – Complete, filled transport packages and unit loads – Unit load dimensions ISO 3677:2016 Filler metal for soldering and brazing — Designation ISO 3678:1976 Paints and varnishes — Print-free test [Withdrawn: replaced with ISO 9117-6] ISO 3679:2015 Determination of flash no-flash and flash point — Rapid equilibrium closed cup method ISO 3680:2004 Determination of flash/no flash — Rapid equilibrium closed cup method [Withdrawn: replaced with ISO 3679] ISO 3681:2018 Binders for paints and varnishes — Determination of saponification value — Titrimetric method ISO 3682:1996 Binders for paints and varnishes — Determination of acid value — Titrimetric method [Withdrawn: replaced with ISO 2114] ISO 3683:1978 Soft soldered joints — Determination of shear strength [Withdrawn: replaced with ISO 5187] ISO 3684:1990 Conveyor belts — Determination of minimum pulley diameters ISO 3685:1993 Tool-life testing with single-point turning tools ISO 3686: Test conditions for high accuracy turret and single spindle coordinate drilling and boring machines with table of fixed height with vertical spindle — Testing of the accuracy ISO 3686-1:2000 Part 1: Single column type machines ISO 3686-2:2000 Part 2: Portal type machines with moving table ISO 3687:1976 Paper and board — Determination of air resistance (Gurley) [Withdrawn without replacement] ISO 3688:1999 Pulps — Preparation of laboratory sheets for the measurement of diffuse blue reflectance factor (ISO brightness) ISO 3689:1983 Paper and board — Determination of bursting strength after immersion in water ISO 3690:2018 Welding and allied processes — Determination of hydrogen content in arc weld metal ISO 3691 Industrial trucks — Safety requirements and verification ISO 3691-1:2011 Part 1: Self-propelled industrial trucks, other than driverless trucks, variable-reach trucks and burden-carrier trucks ISO 3691-2:2016 Part 2: Self-propelled variable-reach trucks ISO 3691-3:2016 Part 3: Additional requirements for trucks with elevating operator position and trucks specifically designed to travel with elevated loads ISO 3691-4:2020 Part 4: Driverless industrial trucks and their systems ISO 3691-5:2014 Part 5: Pedestrian-propelled trucks ISO 3691-6:2021 Part 6: Burden and personnel carriers ISO/TS 3691-7:2011 Part 7: Regional requirements for countries within the European Community [Withdrawn without replacement] ISO 3692:1976 Information processing – Reels and cores for 25,4 mm (1 in) perforated paper tape for information interchange – Dimensions [Withdrawn without replacement] ISO 3693:1977 Nitric acid for industrial use — Determination of chloride ions content — Potentiometric method [Withdrawn without replacement] ISO 3694:1977 Ammonium sulphate for industrial use — Determination of chloride ions content — Potentiometric method [Withdrawn without replacement] ISO 3695:1977 Ammonium nitrate for industrial use — Determination of chloride ions content — Potentiometric method [Withdrawn without replacement] ISO 3696:1987 Water for analytical laboratory use — Specification and test methods ISO 3697:1976 Sodium hydroxide for industrial use — Determination of calcium and magnesium contents — Flame atomic absorption method [Withdrawn without replacement] ISO 3698:1976 Potassium hydroxide for industrial use — Determination of calcium and magnesium contents — Flame atomic absorption method [Withdrawn without replacement] ISO 3699:1976 Anhydrous hydrogen fluoride for industrial use — Determination of water content — Karl Fischer method ISO 3700:1980 Anhydrous hydrogen fluoride for industrial use — Determination of water content — Conductimetric method [Withdrawn without replacement] ISO 3701:1976 Anhydrous hydrogen fluoride for industrial use — Determination of hexafluorosilicic acid content — Reduced molybdosilicate photometric method [Withdrawn without replacement] ISO 3702:1976 Anhydrous hydrogen fluoride for industrial use — Determination of sulphur dioxide content — Iodometric method [Withdrawn without replacement] ISO 3703:1993 Acid-grade and ceramic-grade fluorspar — Determination of flotation agents [Withdrawn without replacement] ISO 3704:1976 Sulphur for industrial use — Determination of acidity — Titrimetric method ISO 3705:1976 Sulphur for industrial use — Determination of arsenic content — Silver diethyldithiocarbamate photometric method ISO 3706:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of total phosphorus (V) oxide content — Quinoline phosphomolybdate gravimetric method ISO 3707:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of calcium content — Flame atomic absorption method [Withdrawn without replacement] ISO 3708:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of chloride content — Potentiometric method [Withdrawn without replacement] ISO 3709:1976 Phosphoric acid for industrial use (including foodstuffs) — Determination of oxides of nitrogen content — 3,4- Xylenol spectrophotometric method [Withdrawn without replacement] ISO 3710:1990 Lead chrome green pigments — Specifications and methods of test [Withdrawn without replacement] ISO 3711:1990 Lead chromate pigments and lead chromate-molybdate pigments — Specifications and methods of test ISO 3713:1987 Ferroalloys – Sampling and preparation of samples – General rules ISO 3714:1980 Oil of pennyroyal [Withdrawn without replacement] ISO 3715 Ships and marine technology – Propulsion plants for ships ISO 3715-1:2002 Part 1: Vocabulary for geometry of propellers ISO 3715-2:2001 Part 2: Vocabulary for controllable-pitch propeller plants ISO 3716:2021 Hydrometry – Functional requirements and characteristics of suspended-sediment samplers ISO/TR 3717:1975 Textile glass — Mats and woven fabrics — Determination of wet-out time through resin [Withdrawn without replacement] ISO/TR 3718:1975 Textile glass — Determination of wet-through time through resin [Withdrawn without replacement] ISO 3719:1994 Mechanical vibration — Symbols for balancing machines and associated instrumentation [Withdrawn without replacement] ISO 3720:2011 Black tea — Definition and basic requirements ISO 3721:2023 Information technology — Computer graphics, image processing and environmental data representation — Information model for Mixed and Augmented Reality Contents - Core Objects and Attributes [original draft was Rigid cellular practice — classification and designation] ISO 3722:1976 Hydraulic fluid power — Fluid sample containers — Qualifying and controlling cleaning methods ISO 3723:2015 Hydraulic fluid power — Filter elements — Method for end load test ISO 3724:2007 Hydraulic fluid power — Filter elements — Determination of resistance to flow fatigue using particulate contaminant ISO 3725:2023 Ships and marine technology — Aquatic nuisance species — Methods for evaluating the performance of compliance monitoring devices for ballast water discharges [original draft was Statistics – Symbols, merged into ISO 3534] ISO 3726:1983 Instant coffee — Determination of loss in mass at 70 degrees C under reduced pressure ISO 3727 Butter — Determination of moisture, non-fat solids and fat contents ISO 3727-1:2001 Part 1: Determination of moisture content (Reference method) ISO 3727-2:2001 Part 2: Determination of non-fat solids content (Reference method) ISO 3727-3:2003 Part 3: Calculation of fat content ISO 3728:2004 Ice-cream and milk ice — Determination of total solids content (Reference method) ISO 3729:1976 Fibre building boards — Determination of surface stability [Withdrawn without replacement] ISO 3730:2012 Shipbuilding and marine structures — Mooring winches ISO 3731:2003 Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole connector type 24 S (supplementary) for vehicles with 24 V nominal supply voltage ISO 3732:2003 Road vehicles — Connectors for the electrical connection of towing and towed vehicles — 7-pole connector type 12 S (supplementary) for vehicles with 12 V nominal supply voltage ISO 3733:1999 Petroleum products and bituminous materials — Determination of water — Distillation method ISO 3734:1997 Petroleum products — Determination of water and sediment in residual fuel oils — Centrifuge method ISO 3735:1999 Crude petroleum and fuel oils — Determination of sediment — Extraction method ISO 3736 Digital fitting — Service process [original draft was Standard atmospheres for conditioning and/or testing — Specifications was numbered ISO 554 to replace ISO/R 554] ISO/TD 3736-1:2022 Part 1: Ready-to-wear clothing online and off-line ISO/TD 3736-2:2022 Part 2: Customized clothing online and off-line ISO 3737:1976 Agricultural tractors and self-propelled machines — Test method for enclosure pressurization systems [Withdrawn: replaced with ISO 14269-(1-5)] ISO 3738 Hardmetals — Rockwell hardness test (scale A) ISO 3738-1:1982 Part 1: Test method ISO 3738-2:1988 Part 2: Preparation and calibration of standard test blocks ISO 3739 Industrial tyres and rims ISO 3739-1:2007 Part 1: Pneumatic tyres (metric series) on 5 degrees tapered or flat base rims ISO 3739-2:2021 Part 2: Pneumatic tyres (metric series) on 5 degrees tapered or flat base rims — Load ratings ISO 3739-3:2021 Part 3: Rims ISO 3740:2019 Acoustics – Determination of sound power levels of noise sources – Guidelines for the use of basic standards ISO 3741:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for reverberation test rooms ISO 3742:1988 Acoustics — Determination of sound power levels of noise sources — Precision methods for discrete-frequency and narrow-band sources in reverberation rooms [Withdrawn: replaced with ISO 3741] ISO 3743 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for small movable sources in reverberant fields ISO 3743-1:2010 Part 1: Comparison method for a hard-walled test room ISO 3743-2:2018 Part 2: Methods for special reverberation test rooms ISO 3744:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for an essentially free field over a reflecting plane ISO 3745:2012 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for anechoic rooms and hemi-anechoic rooms ISO 3746:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Survey method using an enveloping measurement surface over a reflecting plane ISO 3747:2010 Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering/survey methods for use in situ in a reverberant environment ISO 3748 Acoustics — Determination of sound power levels of noise sources — Engineering method for small, nearly omnidirectional sources under free-field conditions over a reflecting plane [Rejected draft] ISO 3749:2022 Glass syringes — Determination of extractable tungsten [Original draft with this number unknown] ISO 3750:2006 Zinc alloys — Determination of magnesium content — Flame atomic absorption spectrometric method ISO 3751:1976 Zinc ingots — Selection and preparation of samples for chemical analysis [Withdrawn: replaced with ISO 20081] ISO 3752:1976 Zinc alloy ingots — Selection and preparation of samples for chemical analysis [Withdrawn: replaced with ISO 20081] ISO 3753:1977 Vacuum technology — Graphical symbols [Withdrawn without replacement] ISO 3754:1976 Steel — Determination of effective depth of hardening after flame or induction hardening [Withdrawn: replaced with ISO 18203] ISO 3755:1991 Cast carbon steels for general engineering purposes [Withdrawn: replaced with ISO 14737] ISO 3756:1976 Oil of cubeb ISO 3757:2002 Oil of patchouli (Pogostemon cablin (Blanco) Benth.) ISO 3758:2012 Textiles — Care labelling code using symbols ISO 3759:2011 Textiles — Preparation, marking and measuring of fabric specimens and garments in tests for determination of dimensional change ISO 3760:2002 Oil of celery seed (Apium graveolens L.) ISO 3761:2005 Oil of rosewood, Brazilian type (Aniba rosaeodora Ducke or Aniba parviflora (Meisn.) Mez.) ISO 3762:1979 Paper — Preparation of a letterpress print for test purposes [Withdrawn without replacement] ISO 3763:1976 Wrought steels — Macroscopic methods for assessing the content of non-metallic inclusions ISO 3764:2016 Timekeeping instruments — Movements — Types, dimensions and nomenclature ISO 3765:1998 Timekeeping instruments — Wristwatches — Dimensions of bracelet-to-case fastening elements ISO 3766:2003 Construction drawings – Simplified representation of concrete reinforcement ISO 3767 Tractors, machinery for agriculture and forestry, powered lawn and garden equipment – Symbols for operator controls and other displays ISO 3767-1:2016 Part 1: Common symbols ISO 3767-2:2016 Part 2: Symbols for agricultural tractors and machinery ISO 3767-3:2016 Part 3: Symbols for powered lawn and garden equipment ISO 3767-4:2016 Part 4: Symbols for forestry machinery ISO 3767-5:2016 Part 5: Symbols for manual portable forestry machines ISO 3768:1976 Metallic coatings — Neutral salt spray test (NSS test) [Withdrawn: replaced with ISO 9227] ISO 3769:1976 Metallic coatings — Neutral salt spray test (NSS test) [Withdrawn: replaced with ISO 9227] ISO 3770:1976 Metallic coatings — Copper-accelerated acetic acid salt spray test (CASS test) [Withdrawn: replaced with ISO 9227] ISO 3771:2011 Petroleum products — Determination of base number — Perchloric acid potentiometric titration method ISO 3772:2000 Photography — Rolls of sensitized material for the pre-press industry — Dimensions and related requirements ISO 3773:1983 Cinematography — Tape splices for 8 mm Type S motion-picture film for projector use — Dimensions ISO 3774:1988 Cinematography — 35 mm motion-picture film perforated 8 mm Type S (1-3-5-7-0) and (1-0) — Cutting and perforating dimensions ISO 3775:1990 Cinematography — Printed 8 mm Type S image area on 16 mm motion-picture film perforated 8 mm Type S (1-3) — Position and dimensions [Withdrawn without replacement] ISO 3776 Tractors and machinery for agriculture — Seat belts ISO 3776-1:2006 Part 1: Anchorage location requirements ISO 3776-2:2013 Part 2: Anchorage strength requirements ISO 3776-3:2009 Part 3: Requirements for assemblies ISO 3777:1976 Radiographic inspection of resistance spot welds for aluminium and its alloys — Recommended practice [Withdrawn without replacement] ISO/TR 3778:1987 Agricultural tractors — Maximum actuating forces required to operate controls [Withdrawn: replaced with ISO 15077] ISO 3779:2009 Road vehicles — Vehicle identification number (VIN) — Content and structure ISO 3780:2009 Road vehicles — World manufacturer identifier (WMI) code ISO 3781:2011 Paper and board — Determination of tensile strength after immersion in water ISO 3782:1980 Paper and board — Determination of resistance to picking — Accelerating speed method using the IGT tester (Pendulum or spring model) [Withdrawn without replacement] ISO 3783:2006 Paper and board — Determination of resistance to picking — Accelerated speed method using the IGT-type tester (electric model) ISO 3784:1976 Road vehicles — Measurement of impact velocity in collision tests ISO 3785:2006 Metallic materials — Designation of test specimen axes in relation to product texture ISO 3786:1975 Shipbuilding — Inland navigation towing hooks — Scale of tractive efforts [Withdrawn without replacement] ISO 3787:1976 Wood — Test methods — Determination of ultimate stress in compression parallel to grain [Withdrawn: replaced with ISO 13061-167] ISO/IEC 3788:1990 Information processing – 9-track, 12,7 mm (0,5 in) wide magnetic tape for information interchange using phase encoding at 126 ftpmm (3 200 ftpi), 63 cpmm (1 600 cpi) ISO 3789 Tractors, machinery for agriculture and forestry, powered lawn and garden equipment — Location and method of operation of operator controls ISO 3789-1:1982 Part 1: Common controls [Withdrawn: replaced with ISO 15077] ISO 3789-2:1982 Part 2: Controls for agricultural tractors and machinery [Withdrawn: replaced with ISO 15077] ISO 3790:1976 Fishing nets — Determination of elongation of netting yarns ISO 3791:1976 Office machines and data processing equipment – Keyboard layouts for numeric applications ISO 3792:1976 Adding machines – Layout of function keyboard ISO 3793:1976 Essential oils — Estimation of primary and secondary free alcohols content by acetylation in pyridine [Withdrawn without replacement] ISO 3794:1976 Essential oils (containing tertiary alcohols) — Estimation of free alcohols content by determination of ester value after acetylation ISO 3795:1989 Road vehicles, and tractors and machinery for agriculture and forestry — Determination of burning behaviour of interior materials ISO 3796:1999 Ships and marine technology — Clear openings for external single-leaf doors ISO 3797:1976 Shipbuilding — Vertical steel ladders ISO 3798:1976 Tinplate and blackplate — Minimum packaging requirements [Withdrawn without replacement] ISO 3799:1976 Textile machinery and accessories — Hydraulic lubricating fittings for textile machinery [Withdrawn without replacement] ISO 3800:1993 Threaded fasteners — Axial load fatigue testing — Test methods and evaluation of results ISO 3801:1977 Textiles — Woven fabrics — Determination of mass per unit length and mass per unit area ISO 3802:1976 Information processing – General purpose reels with 8 mm (5/16 in) centre hole for magnetic tape for interchange instrumentation applications ISO 3803:1984 Road vehicles — Hydraulic pressure test connection for braking equipment ISO 3804:1977 Plywood — Determination of dimensions of test pieces [Withdrawn: replaced with ISO 9424] ISO 3805:1977 Plywood — Determination of density [Withdrawn: replaced with ISO 9427] ISO 3806:1977 Plywood — Determination of moisture content [Withdrawn: replaced with ISO 9425] ISO 3807:2013 Gas cylinders — Acetylene cylinders — Basic requirements and type testing ISO 3808:2002 Road vehicles — Unscreened high-voltage ignition cables — General specifications, test methods and requirements ISO 3809:2004 Oil of lime (cold pressed), Mexican type (Citrus aurantifolia (Christm.) Swingle), obtained by mechanical means ISO 3810:1987 Floor tiles of agglomerated cork — Methods of test ISO 3811:1979 Meat and meat products — Detection and enumeration of presumptive coliform bacteria and presumptive Escherichia coli — (Reference method) [Withdrawn: replaced with ISO 4831, ISO 4832, and ISO 7251] ISO 3812:1976 Essential oils of geranium and rose — Determination of ester value after hot formylation ISO 3813:2004 Resilient floor coverings — Cork floor tiles — Specification [Withdrawn without replacement] ISO/TS 3814:2014 Standard tests for measuring reaction-to-fire of products and materials — Their development and application ISO 3815 Zinc and zinc alloys ISO 3815-1:2005 Part 1: Analysis of solid samples by optical emission spectrometry ISO 3815-2:2005 Part 2: Analysis by inductively coupled plasma optical emission spectrometry ISO 3816:1976 Zinc ingots — Selection and preparation of samples for spectrographic analysis [Withdrawn: replaced with ISO 20081] ISO 3817:1976 Zinc alloy ingots — Selection and preparation of samples for spectrographic analysis [Withdrawn: replaced with ISO 20081] ISO/TR 3818:1977 Ropes and cordage — Rope assemblies used in slinging — Safe working loads [Withdrawn without replacement] ISO 3819:2015 Laboratory glassware – Beakers ISO 3820:1978 Cinematography — Sprockets for 8 mm Type S motion-picture film — Dimensions and design ISO 3821:2019 Gas welding equipment — Rubber hoses for welding, cutting and allied processes ISO 3822 Acoustics – Laboratory tests on noise emission from appliances and equipment used in water supply installations ISO 3822-1:1999 Part 1: Method of measurement ISO 3822-2:1995 Part 2: Mounting and operating conditions for draw-off taps and mixing valves ISO 3822-3:2018 Part 3: Mounting and operating conditions for in-line valves and appliances ISO 3822-4:1997 Part 4: Mounting and operating conditions for special appliances ISO 3823 Dental rotary instruments — Burs ISO 3823-1:1997 Part 1: Steel and carbide burs ISO 3823-2:2003 Part 2: Finishing burs ISO 3824:1984 Dental silicophosphate cement (hand-mixed) [Withdrawn: replaced with ISO 9917] ISO 3825:1977 Glass transfusion bottles for medical use — Chemical resistance [Withdrawn without replacement] ISO 3826 Plastics collapsible containers for human blood and blood components ISO 3826-1:2013 Part 1: Conventional containers ISO 3826-2:2008 Part 2: Graphical symbols for use on labels and instruction leaflets ISO 3826-3:2006 Part 3: Blood bag systems with integrated features ISO 3826-4:2015 Part 4: Aphaeresis blood bag systems with integrated features ISO 3827 Shipbuilding — Co-ordination of dimensions in ships' accommodation ISO 3827-1:1977 Part 1: Principles of dimensional co-ordination ISO 3827-2:1977 Part 2: Glossary of terms ISO 3827-3:1977 Part 3: Co-ordinating sizes for components and assemblies ISO 3827-4:1977 Part 4: Controlling dimensions ISO 3827-5:1979 Part 5: Co-ordinating sizes for key components ISO 3828:2008 Shipbuilding and marine structures – Deck machinery – Vocabulary and symbols ISO 3829 Petroleum products – Determination of density and relative density – Jaulmes pyknometer method [Rejected draft] ISO 3830:1993 Petroleum products — Determination of lead content of gasoline — Iodine monochloride method ISO 3831:1979 Timekeeping instruments — Classification and numbering system and nomenclature of components for watches and clocks [Withdrawn without replacement] ISO 3832:2002 Passenger cars — Luggage compartments — Method of measuring reference volume ISO 3833:1977 Road vehicles – Types – Terms and definitions ISO 3834 Quality requirements for fusion welding of metallic materials ISO 3834-1:2021 Part 1: Criteria for the selection of the appropriate level of quality requirements ISO 3834-2:2021 Part 2: Comprehensive quality requirements ISO 3834-3:2021 Part 3: Standard quality requirements ISO 3834-4:2021 Part 4: Elementary quality requirements ISO 3834-5:2021 Part 5: Documents with which it is necessary to conform to claim conformity to the quality requirements of ISO 3834-2, ISO 3834-3 or ISO 3834-4 ISO 3834-6:2024 Part 6: Guidelines on implementing the ISO 3834 series ISO 3835 Equipment for vine cultivation and wine making – Vocabulary ISO 3835-1:1976 (No part title) ISO 3835-2:1977 (No part title) [Withdrawn without replacement] ISO 3835-3:1980 (No part title) ISO 3835-4:1981 (No part title) ISO 3835-5:1982 (No part title) [Withdrawn without replacement] ISO/TR 3836:1978 Shoe sizes — System of width grading (for use in the Mondopoint system) [Withdrawn without replacement] ISO 3837:1993 Liquid petroleum products — Determination of hydrocarbon types — Fluorescent indicator adsorption method ISO 3838:2004 Crude petroleum and liquid or solid petroleum products — Determination of density or relative density — Capillary-stoppered pyknometer and graduated bicapillary pyknometer methods ISO 3839:1996 Petroleum products — Determination of bromine number of distillates and aliphatic olefins — Electrometric method ISO 3840:1976 Petroleum distillates — Determination of olefinic plus aromatic hydrocarbons content [Withdrawn without replacement] ISO 3841:1977 Petroleum waxes — Determination of melting point (cooling curve) [Withdrawn without replacement] ISO 3842:2006 Road vehicles — Fifth wheels — Interchangeability ISO 3843 Dentistry — Dental attachments — Measurement of placement and removal forces [Under development; original draft named ISO 2135 as it was a revision of ISO/R 2135] ISO 3844:1975 Shoe sizes — Method of marking [Withdrawn: replaced with ISO 9407] ISO 3845:2024 Oil and gas industries including lower carbon energy — Full ring ovalization test method for the evaluation of the cracking resistance of steel line pipe in sour service [original draft was Petroleum and natural gas industries — High-test steel line pipe] ISO 3846:2008 Hydrometry – Open channel flow measurement using rectangular broad-crested weirs ISO 3847:1977 Liquid flow measurement in open channels by weirs and flumes – End-depth method for estimation of flow in rectangular channels with a free overfall [Withdrawn: replaced with ISO 18481] ISO 3848:2016 Essential oil of citronella, Java type ISO 3849:2003 Oil of citronella, Sri Lankan type (Cymbopogon nardus (L.) W. Watson var. lenabatu Stapf.) ISO 3850:2004 Resilient floor coverings – Determination of apparent density of composition cork ISO 3851:1977 Capsulated dental silicate and silico-phosphate filling materials [Withdrawn: replaced with ISO 9917] ISO 3852:2007 Iron ores for blast furnace and direct reduction feedstocks — Determination of bulk density ISO 3853:1994 Road vehicles — Towing vehicle coupling device to tow caravans or light trailers — Mechanical strength test ISO 3854:1976 Road vehicles — Caravans and light trailers — Vacuum braking — Measurement of reaction time [Withdrawn without replacement] ISO 3855:1977 Milling cutters – Nomenclature ISO 3856 Paints and varnishes — Determination of "soluble" metal content ISO 3856-1:1984 Part 1: Determination of lead content — Flame atomic absorption spectrometric method and dithizone spectrophotometric method ISO 3856-2:1984 Part 2: Determination of antimony content — Flame atomic absorption spectrometric method and Rhodamine B spectrophotometric method ISO 3856-3:1984 Part 3: Determination of barium content — Flame atomic emission spectrometric method ISO 3856-4:1984 Part 4: Determination of cadmium content — Flame atomic absorption spectrometric method and polarographic method ISO 3856-5:1984 Part 5: Determination of hexavalent chromium content of the pigment portion of the liquid paint or the paint in powder form — Diphenylcarbazide spectrophotometric method ISO 3856-6:1984 Part 6: Determination of total chromium content of the liquid portion of the paint — Flame atomic absorption spectrometric method ISO 3856-7:1984 Part 7: Determination of mercury content of the pigment portion of the paint and of the liquid portion of water-dilutable paints — Flameless atomic absorption spectrometric method ISO 3857 Compressors, pneumatic tools and machines – Vocabulary ISO 3857-1:1977 Part 1: General ISO 3857-2:1977 Part 2: Compressors ISO 3857-3:1989 Part 3: Pneumatic tools and machines ISO 3857-4:2012 Part 4: Air treatment ISO 3858:2018 Rubber compounding ingredients — Carbon black — Determination of light transmittance of toluene extract ISO 3859:2000 Inverse dovetail cutters and dovetail cutters with cylindrical shanks ISO 3860:2011 Bore cutters with key drive — Form milling cutters with constant profile ISO 3861:2005 Rubber hoses and hose assemblies for sand and grit blasting — Specification ISO 3862:2020 Rubber hoses and hose assemblies — Rubber-covered spiral-wire-reinforced hydraulic types for oil-based or water-based fluids — Specification ISO 3863:1989 Cylindrical cork stoppers — Dimensional characteristics, sampling, packaging and marking [Withdrawn without replacement] ISO 3864 Graphical symbols – Safety colours and safety signs ISO 3865:2020 Rubber, vulcanized or thermoplastic — Methods of test for staining in contact with organic material ISO 3866:1977 Office machines and printing machines used for information processing – Widths of fabric printing ribbons on spools exceeding 19 mm ISO 3867:2017 Composition cork — Expansion joint fillers — Test methods ISO 3868:1976 Metallic and other non-organic coatings — Measurement of coating thicknesses — Fizeau multiple-beam interferometry method ISO 3869:2017 Agglomerated cork — Expansion joint fillers — Specifications, packaging and marking ISO 3870:1976 Conveyor belts (fabric carcass), with length between pulley centres up to 300 m, for loose bulk materials — Adjustment of take-up device [Withdrawn without replacement] ISO 3871:2000 Road vehicles — Labelling of containers for petroleum-based or non-petroleum-based brake fluid ISO 3872:1976 Graphic technology — Sheet-fed printing machines — Range of sizes [Withdrawn without replacement] ISO 3873:1977 Industrial safety helmets ISO 3874:2017 Series 1 freight containers — Handling and securing ISO 3875:2020 Machine tools — Test conditions for external cylindrical centreless grinding machines — Testing of the accuracy ISO 3876:1986 Shipbuilding — Inland vessels — Hand-holes [Withdrawn without replacement] ISO 3877 Tyres, valves and tubes – List of equivalent terms ISO 3877-1:1997 Part 1: Tyres ISO 3877-2:1997 Part 2: Tyre valves ISO 3877-3:1978 Part 3: Tubes ISO 3877-4:1984 Part 4: Solid tyres ISO 3878:1983 Hardmetals — Vickers hardness test [Withdrawn without replacement] ISO 3879:1977 Welded joints — Recommended practice for liquid penetrant testing [Withdrawn: replaced with ISO 3452] ISO 3880 Building construction – Stairs – Vocabulary ISO 3880-1:1977 [Withdrawn without replacement] ISO 3881:1977 Building construction — Modular co-ordination — Stairs and stair openings — Co-ordinating dimensions ISO 3882:2003 Metallic and other inorganic coatings — Review of methods of measurement of thickness ISO 3883:1977 Office machines – Line and character capacity of address masters ISO 3884:2025 Solid recovered fuels — Methods for the determination of the content of elements (Al, Ca, Fe, K, Mg, Na, P, S, Si, Ti, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Tl, V, Zn) [Original draft was Plastic identification card 1] ISO 3885 Solid recovered fuels — Determination of halogens and sulfur by oxidative pyrohydrolytic combustion followed by ion chromatography [under development; original draft with this number unknown ISO 3886:1986 Iron ores — Determination of manganese content — Periodate spectrophotometric method [Withdrawn: replaced with ISO 9682-2] ISO 3887:2007 Steels — Determination of the depth of decarburization ISO 3888 Passenger cars — Test track for a severe lane-change manoeuvre ISO 3888-1:2018 Part 1: Double lane-change ISO 3888-2:2011 Part 2: Obstacle avoidance ISO 3889:2006 Milk and milk products — Specification of Mojonnier-type fat extraction flasks ISO 3890 Milk and milk products — Determination of residues of organochlorine compounds (pesticides) ISO 3890-1:2009 Part 1: General considerations and extraction methods ISO 3890-2:2009 Part 2: Test methods for crude extract purification and confirmation ISO 3891:1978 Acoustics — Procedure for describing aircraft noise heard on the ground [Withdrawn without replacement] ISO 3892:2000 Conversion coatings on metallic materials — Determination of coating mass per unit area — Gravimetric methods ISO 3893:1977 Concrete — Classification by compressive strength [Withdrawn without replacement] ISO 3894:2015 Road vehicles — Wheels/rims for commercial vehicles — Test methods ISO 3895:1986 Road vehicles — Screened and waterproof spark-plug and its connection — Type 2 ISO 3896:1986 Road vehicles — Screened and waterproof spark-plug and its connection — Type 3 ISO 3897:1997 Photography — Processed photographic plates — Storage practices [Withdrawn: replaced with ISO 18918] ISO 3898:2013 Bases for design of structures — Names and symbols of physical quantities and generic quantities ISO 3899:2005 Rubber — Nitrile latex — Determination of residual acrylonitrile content ISO 3900:1995 Rubber — Nitrile latex — Determination of bound acrylonitrile content ISO 3901:2019 Information and documentation – International Standard Recording Code (ISRC) ISO 3902:1990 Shipbuilding and marine structures — Gaskets for rectangular windows and side scuttles ISO 3903:2012 Ships and marine technology — Ships' ordinary rectangular windows ISO 3904:1990 Shipbuilding and marine structures — Clear-view screens ISO 3905:1980 Paints and varnishes — Determination of contrast ratio (opacity) of light coloured paints at a fixed spreading rate (using black and white charts) [Withdrawn: replaced with ISO 6504-3] ISO 3906:1980 Paints and varnishes — Determination of contrast ratio (opacity) of light coloured paints at a fixed spreading rate (using polyester film) [Withdrawn: replaced with ISO 6504-3] ISO 3907:2009 Hardmetals — Determination of total carbon — Gravimetric method ISO 3908:2009 Hardmetals — Determination of insoluble (free) carbon — Gravimetric method ISO 3909:1976 Hardmetals — Determination of cobalt — Potentiometric method ISO 3910:1983 Rubber boots, unlined moulded [Withdrawn without replacement] ISO 3911:2021 Wheels and rims for pneumatic tyres – Vocabulary, designation and marking ISO 3912:1977 Woodruff keys and keyways [Withdrawn without replacement] ISO 3913:1977 Shipbuilding — Welded steel bollards ISO 3914 Textile machinery and accessories — Cylindrical tubes ISO 3914-1:1994 Part 1: Recommended main dimensions ISO 3914-2:1994 Part 2: Dimensions, tolerances and designation of tubes for open-end spinning machines ISO 3914-3:1994 Part 3: Dimensions, tolerances and designation of tubes for tape yarns ISO 3914-4:1994 Part 4: Dimensions, tolerances and designation of tubes for textured yarns [Withdrawn without replacement] ISO 3914-5:1994 Part 5: Dimensions, tolerances and designation of tubes for continuous spin-drawn synthetic filament yarns [Withdrawn without replacement] ISO 3914-6:1994 Part 6: Dimensions, tolerances and designation of tubes for cross-wound packages in winding and twisting [Withdrawn without replacement] ISO 3914-7:1994 Part 7: Dimensions, tolerances and designation of perforated tubes for cheese dyeing ISO 3915:2022 Plastics — Measurement of resistivity of conductive plastics ISO 3916:1977 Shipbuilding — Inland navigation — Rope tubs [Withdrawn without replacement] ISO 3917:2016 Road vehicles — Safety glazing materials — Test methods for resistance to radiation, high temperature, humidity, fire and simulated weathering ISO 3918:2007 Milking machine installations – Vocabulary ISO 3919:2005 Coated abrasives — Flap wheels with shaft ISO 3920:1976 Honing stones of square section — Designation and dimensions [Withdrawn: replaced with ISO 603-(1-16)] ISO 3921:1976 Honing stones of rectangular section — Designation and dimensions [Withdrawn: replaced with ISO 603-(1-16)] ISO 3922:1978 Continuous mechanical handling equipment — Rotary vane feeder — Dimensional specifications [Withdrawn without replacement] ISO 3923 Metallic powders — Determination of apparent density ISO 3923-1:2018 Part 1: Funnel method ISO 3923-2:1981 Part 2: Scott volumeter method ISO 3923-3:1986 Part 3: Oscillating funnel method [Withdrawn without replacement] ISO 3924:2019 Petroleum products — Determination of boiling range distribution — Gas chromatography method ISO 3925:2014 Unsealed radioactive substances — Identification and documentation ISO 3926:1980 Shipbuilding — Inland navigation — Couplings for oil and fuel reception — Mating dimensions [Withdrawn without replacement] ISO 3927:2017 Metallic powders, excluding powders for hardmetals — Determination of compressibility in uniaxial compression ISO 3928:2016 Sintered metal materials, excluding hardmetals — Fatigue test pieces ISO 3929:2003 Road vehicles — Measurement methods for exhaust gas emissions during inspection or maintenance ISO 3930:2000 Instruments for measuring vehicle exhaust emissions [Withdrawn without replacement] ISO 3931 Fibre building boards – Determination of transversal internal bond [Rejected draft] ISO 3932:1976 Textiles — Woven fabrics — Measurement of width of pieces [Withdrawn: replaced with ISO 22198] ISO 3933:1976 Textiles — Woven fabrics — Measurement of length of pieces [Withdrawn: replaced with ISO 22198] ISO 3934:2021 Rubber, vulcanized and thermoplastic — Preformed gaskets used in buildings — Classification, specifications and test methods ISO 3935:1977 Shipbuilding — Inland navigation — Fire-fighting water system — Pressures [Withdrawn without replacement] ISO 3936:1993 Reduction sleeves with tenon drive with external and internal 7/24 taper — Dimensions ISO 3937 Cutter arbors with tenon drive ISO 3937-1:2008 Part 1: Dimensions of Morse taper ISO 3937-2:2008 Part 2: Dimensions of 7/24 taper ISO 3937-3:2008 Part 3: Dimensions of hollow taper interface with flange contact surface ISO 3938:1986 Hydraulic fluid power — Contamination analysis — Method for reporting analysis data [Withdrawn without replacement] ISO 3939:1977 Fluid power systems and components — Multiple lip packing sets — Methods for measuring stack heights ISO 3940:1977 Tapered die-sinking cutters with parallel shanks ISO 3941:1977 Classification of fires ISO 3942:1976 Photographic grade sodium carbonate, monohydrate — Specification [Withdrawn: replaced with ISO 424] ISO 3943:1993 Photography — Processing chemicals — Specifications for anhydrous sodium acetate ISO 3944:1992 Fertilizers — Determination of bulk density (loose) ISO 3945:1985 Mechanical vibration of large rotating machines with speed range from 10 to 200 r/s — Measurement and evaluation of vibration severity in situ [Withdrawn: replaced with ISO 10816-1] ISO 3946:1982 Starches and derived products — Determination of total phosphorus content — Spectrophotometric method ISO 3947:1977 Starches, native or modified — Determination of total fat content ISO 3948:1977 Shipbuilding — Inland vessels — Compressed-air systems — Pressure ranges [Withdrawn without replacement] ISO 3949:2020 Plastics hoses and hose assemblies — Textile-reinforced types for hydraulic applications — Specification ISO 3950:2016 Dentistry – Designation system for teeth and areas of the oral cavity ISO 3951 Sampling procedures for inspection by variables ISO 3951-1:2022 Part 1: Specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a single quality characteristic and a single AQL ISO 3951-2:2013 Part 2: General specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection of independent quality characteristics ISO 3951-3:2007 Part 3: Double sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection ISO 3951-4:2011 Part 4: Procedures for assessment of declared quality levels ISO 3951-5:2006 Part 5: Sequential sampling plans indexed by acceptance quality limit (AQL) for inspection by variables (known standard deviation) ISO 3952 Kinematic diagrams – Graphical symbols ISO 3952-1:1981 (Motion of links of mechanisms; Kinematic pairs; Links and connections of their components; Linkage of bars and their links) ISO 3952-2:1981 (Friction and gear mechanisms; Cam mechanisms) ISO 3952-3:1979 (Maltese and ratchet mechanisms; Couplings and brakes) ISO 3952-4:1984 (Miscellaneous mechanisms and their components) ISO 3953:2011 Metallic powders — Determination of tap density ISO 3954:2007 Powders for powder metallurgical purposes — Sampling ISO 3955:1977 Sintered metal materials, excluding hardmetals — Sampling [Withdrawn without replacement] ISO/TR 3956:1975 Principles of structural fire-engineering design with special regard to the connection between real fire exposure and the heating conditions of the standard fire-resistance test (ISO 834) ISO 3957:2025 Reaction to fire tests — Façades — Measurement of heat and smoke generation in severe exterior fire scenarios [original draft Graphic symbols — Index, survey, and compilation of the single sheets became ISO 7000] ISO 3958:1996 Passenger cars — Driver hand-control reach ISO 3959:1977 Green bananas — Ripening conditions ISO 3960:2017 Animal and vegetable fats and oils — Determination of peroxide value — Iodometric (visual) endpoint determination ISO 3961:2018 Animal and vegetable fats and oils — Determination of iodine value ISO 3962:1977 Materials and equipment for petroleum and natural gas industries — Tool joints for steel drill pipe for oil or natural gas wells [Withdrawn without replacement] ISO 3963:1977 Fertilizers — Sampling from a conveyor by stopping the belt ISO 3964:2016 Dentistry — Coupling dimensions for handpiece connectors ISO 3965:1990 Agricultural wheeled tractors — Maximum speeds — Method of determination ISO 3966:2020 Measurement of fluid flow in closed conduits – Velocity area method using Pitot static tubes ISO 3967 Petroleum products – Determination of density and relative density – Bingham pyknometer method [Rejected draft] ISO 3968:2017 Hydraulic fluid power — Filters — Evaluation of differential pressure versus flow ISO 3969:1979 Shipbuilding — Inland vessels — Operational documentation [Withdrawn without replacement] ISO 3970:1977 Modular units for machine tool construction — Integral way columns — Floor-mounted type ISO 3971:1977 Rice milling — Symbols and equivalent terms [Withdrawn without replacement] ISO 3972:2011 Sensory analysis — Methodology — Method of investigating sensitivity of taste ISO 3973:1996 Living animals for slaughter — Vocabulary — Bovines [Withdrawn without replacement] ISO 3974:1977 Definitions of living animals for slaughter — Ovines ISO 3975:1977 Definitions of living animals for slaughter — Horses [Withdrawn without replacement] ISO 3976:2006 Milk fat — Determination of peroxide value ISO 3977 Gas turbines – Procurement ISO 3978:1976 Aluminium and aluminium alloys — Determination of chromium — Spectrophotometric method using diphenylcarbazide, after extraction ISO 3979:1977 Aluminium and aluminium alloys — Determination of nickel — Spectrophotometric method using dimethylglyoxime [Withdrawn without replacement] ISO 3980:1977 Aluminium and aluminium alloys — Determination of copper — Atomic absorption spectrophotometric method ISO 3981:1977 Aluminium and aluminium alloys — Determination of nickel — Atomic absorption spectrophotometric method ISO 3982 Chemical analysis of aluminum and its alloys — Complexometric determination of magnesium [Rejected draft] ISO 3983:1977 Cereals and cereal products — Determination of alpha-amylase activity — Colorimetric method [Withdrawn without replacement] ISO 3984:2004 Road vehicles — Rear moving barrier impact test procedure [Withdrawn without replacement] ISO/TR 3985:2021 Biotechnology — Data publication — Preliminary considerations and concepts [Original draft with this number unknown] ISO 3986 Petroleum products — Lubricating wax — Determination of cone penetration [Rejected draft] ISO 3987:2010 Petroleum products — Determination of sulfated ash in lubricating oils and additives ISO 3988 Determination of Spontaneous ignition temperature [Rejected draft] ISO 3989 Measurement of airborne noise emitted by compressor units including prime movers [Rejected draft] ISO 3990:2023 Dentistry — Evaluation of antibacterial activity of dental restorative materials, luting cements, fissure sealants and orthodontic bonding or luting materials [original draft was Modular co-ordination — Sizes for co-ordinating lengths and widths of openings in the horizontal plane] ISO 3991:2025 Agricultural machinery — Robotic feed systems — Safety [original draft was Modular co-ordination — Sizes for co-ordinating heights of openings in the vertical plane] ISO 3992 Petroleum waxes — Determination of needle penetration [Rejected draft] ISO 3993:1984 Liquefied petroleum gas and light hydrocarbons — Determination of density or relative density — Pressure hydrometer method ISO 3994:2014 Plastics hoses — Helical-thermoplastic-reinforced thermoplastics hoses for suction and discharge of aqueous materials — Specification ISO 3995:1985 Metallic powders — Determination of green strength by transverse rupture of rectangular compacts ISO 3996:1995 Road vehicles — Brake hose assemblies for hydraulic braking systems used with non-petroleum-base brake fluid ISO 3997 Bitumen and bituminous binders – Determination of needle penetration [Rejected draft] ISO 3998:1977 Textiles — Determination of resistance to certain insect pests ISO 3999:2004 Radiation protection — Apparatus for industrial gamma radiography — Specifications for performance, design and tests
Cracking breaks larger molecules into smaller ones. This reaction requires heat and catalysts. The thermal cracking process follows a homolytic mechanism with formation of free radicals. The catalytic cracking process involves the presence of acid catalysts (usually solid acids such as silica-alumina and zeolites), which promote a heterolytic (asymmetric) breakage of bonds yielding pairs of ions of opposite charges, usually a carbocation. Carbon-localized free radicals and cations are both highly unstable and undergo processes of chain rearrangement, C–C scission in position beta (i.e., cracking) and intra- and intermolecular hydrogen transfer or hydride transfer. In both types of processes, the corresponding reactive intermediates (radicals, ions) are permanently regenerated, and thus they proceed by a self-propagating chain mechanism. The chain of reactions is eventually terminated by radical or ion recombination.
Sources: en.wikipedia.org
The Royal Italian Army ate mainly pasta, white bread, oatmeal, meat, fish, broth, salad, sugar, cheese, and butter from their field kitchens, with alcohol and desserts also issued. However, on the front, Italian soldiers often had to live off of canned tuna, ham, soup, black bread, and pasta. The canned food issued to soldiers on deployment was of low quality, and Italian soldiers had to drink water out of and cook pasta in unwashed gasoline drums, leading to gasoline-flavored water and pasta. Regular supplies of food were strained by logistical issues during the North African campaign.
Cross-flowing is a passive formation method that involves the continuous and aqueous phases running at an angle to each other. Most commonly, the channels are perpendicular in a T-shaped junction with the dispersed phase intersecting the continuous phase; other configurations such as a Y-junction are also possible. The dispersed phase extends into the continuous and is stretched until shear forces break off a droplet. In a T-junction, droplet size and formation rate are determined by the flow rate ratio and capillary number. The capillary number relates the viscosity of the continuous phase, the superficial velocity of the continuous phase, and the interfacial tension. Typically, the dispersed phase flow rate is slower than the continuous flow rate. T-junction formation can be further applied by adding additional channels, creating two T-junctions at one location. By adding channels, different dispersed phases can be added at the same point to create alternating droplets of different compositions. Droplet size, usually above 10 μm, is limited by the channel dimensions and often produces droplets with a CV of less than 2% with a rate of up to 7 kHz.
Volatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. They are common and exist in a variety of settings and products, not limited to upholstered furniture, arts and crafts supplies, dry cleaned clothing, and cleaning supplies. VOCs are responsible for the odor of scents and perfumes as well as pollutants. They play an important role in communication between animals and plants, such as attractants for pollinators, protection from predation, and even inter-plant interactions. Some VOCs are dangerous to human health or cause harm to the environment, often despite the odor being perceived as pleasant, such as "new car smell". Anthropogenic VOCs are regulated by law, especially indoors, where concentrations are the highest. Most VOCs are not acutely toxic, but may have long-term chronic health effects. Some VOCs have been used in pharmaceutical settings, while others are the target of administrative controls because of their recreational use. The high vapor pressure of VOCs correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a trait known as volatility.
Sources: en.wikipedia.org
== Pultronics today == Today (>1998), Pultronics is involved in the RFID industry with its active RFID systems for long-range wireless data communications. Tracking of goods/assets through a cold chain is a typical usage of such systems. Pultronics is also active in the micro-transmitter system design including design of ASICs resulting in miniature sized active tags.
Lindow Moss is a peat bog in Lindow, an area of Wilmslow, Cheshire, which has been used as common land since the medieval period. It formed after the last ice age, one of many such peat bogs in north-east Cheshire and the Mersey basin that formed in hollows caused by melting ice. Investigations have not yet discovered settlement or agricultural activity around the edge of Lindow Moss that would have been contemporary with Lindow Man, but analysis of pollen in the peat suggests there was some cultivation in the vicinity. Once covering over 600 hectares (1,500 acres), the bog has now shrunk to a tenth of its original size. It is a dangerous place and an 18th-century writer recorded people drowning there. For centuries, the peat from the bog was used as fuel, and it continued to be extracted until the 1980s, by which time the process had been mechanised. Lindow Moss is a lowland raised mire, a type of peat bog which often produces the best-preserved bog bodies, allowing more detailed analysis. Lowland raised mires occur mainly in northern England and extend south to the Midlands. Lindow Man is one of 27 bodies to be recovered from such areas.
== June 2, 1915 (Wednesday) == Second Battle of Artois — The French bombarded German defenses around Neuville-Saint-Vaast, France for three days before launching an attack. Shabin-Karahisar uprising — An Armenian militia of 250 began a month-long resistance against the Ottoman Empire in response to the Armenian genocide using a fort in the Giresun Province of Turkey. Ceylon Governor Robert Chalmers declared martial law in the colony (now Sri Lanka) after violent unrest between Muslim and Buddhist broke out in Kandy and spread to other towns and cities. The Imperial German Army established the 83rd and 84th Infantry Divisions. Born: Walter Tetley, American voice actor, best known as the voice of "Sherman" in the TV cartoon Mr. Peabody; as Walter Campbell Tetzlaff, in New York City, United States (d. 1975) Lester del Rey, American science fiction writer and publisher, editor with wife Judy-Lynn del Rey of Del Rey Books; as Leonard Knapp, in Saratoga Township, Winona County, Minnesota, United States (d. 1993) Li Lili, Chinese actress, known for film roles in Little Toys and The Big Road; as Qian Zhenzhen, in Beijing, Republic of China (present-day China) (d. 2005) Died: George Randell, 84, Australian politician, Member of the Western Australian Legislative Council from 1873 to 1875 and 1880 to 1890 (b. 1830) Dave Orr, 55, American baseball player, first baseman for various teams including the New York Metropolitans and the Brooklyn Bridegrooms from 1883 to 1890 (b. 1859)
Sources: en.wikipedia.org
Size-exclusion chromatography is the most common method, often calibrated with protein standards of known molecular weight. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) can provide a visual profile. Mass spectrometry is used for detailed peptide sequencing.
The powder should be kept in a sealed container in a cool, dry place away from direct sunlight. Moisture exposure can cause clumping, so desiccants may be used. Once dissolved, solutions require refrigeration or preservatives to prevent microbial growth.
Common checks include moisture content, ash, protein content, heavy metals, and microbial counts. The degree of hydrolysis and molecular weight distribution are also measured. These parameters help ensure consistency and safety.
Gelatin is a partially hydrolyzed form of collagen that retains the ability to form gels in water. Collagen peptides undergo more extensive hydrolysis, resulting in shorter chains that dissolve in cold water without gelling. The two products differ in molecular weight distribution and functional behavior.