natgillin/translations-raw huggingface dataset:
In addition, the impacting surface shall extend over the entire width of the vehicle struck;
Poleg tega mora udarna površina segati čez celotno širino udarjenega vozila;
The ground clearance of the lower edge of the impacting surface shall be 175 ± 25 mm.
razdalja od tal do spodnjega roba udarne površine mora biti 175 ± 25 mm.
Special provisions applicable where a moving barrier is used
Posebne določbe za uporabo premične pregrade
If the impactor is secured to a carriage (moving barrier) by a restraining element, the latter shall be rigid and be incapable of being deformed by the collision; the carriage shall at the moment of collision be capable of moving freely and no longer be subject to the action of the propelling device.
Če je udarna naprava pritrjena na voziček (premična pregrada) s pritrdilnim delom, mora biti slednji tog in ne sme biti mogoče, da se pri trku deformira; v trenutku trka mora biti mogoče prosto premikanje vozička, ki ne sme več biti pod vplivom pogonske naprave.
The velocity of collision shall be between 48 km/h and 52 km/h.
Hitrost ob trku mora biti med 48 in 52 km/h.
The aggregate weight (mass) of carriage and impactor shall be 1100 ± 20 kg.
Skupna teža (masa) vozička in udarne naprave mora biti 1100 ± 20 kg.
Special provisions applicable where a pendulum is used
Posebne določbe za uporabo nihala
The distance between the centre of the impacting face and the axis of rotation of the pendulum shall be not less than 5 m.
Razdalja med središčem udarne stranice in vrtilne osi nihala ne sme biti manjša od 5 m.
The impactor shall be freely suspended by rigid arms rigidly secured to it.
Udarna naprava mora biti prosto obešena na togih nosilcih, ki so togo pripeti nanjo.
Arresting gear shall be incorporated in the pendulum to prevent any secondary collision by the impactor on the test vehicle.
V nihalo je vdelana naprava za zadržanje, ki preprečuje vsak naknadni trk udarne naprave in preskusnega vozila.
At the moment of collision the velocity of the centre of percussion of the pendulum shall be between 48 and 52 km/h.
V trenutku trka mora biti hitrost središča udarca nihala med 48 in 52 km/h.
The reduced mass ‘mr’ at the centre of percussion of the pendulum is defined as a function of the total mass ‘m’, of the distance ‘a’ [1] between the centre of percussion and the axis of rotation, and of the distance ‘l’ between the centre of gravity and the axis of rotation, by the following equation:
Zmanjšana masa „mr“ v središču udarca nihala je opredeljena kot funkcija skupne mase „m“, razdalje „a“ [1] med središčem udarca in vrtilno osjo ter razdalje „l“ med težiščem in vrtilno osjo, in sicer z naslednjo enačbo:
The reduced mass mr shall be 1100 ± 20 kg.
Zmanjšana masa mr mora znašati 1100 ± 20 kg.
General provisions relating to the mass and velocity of the impactor
Splošne določbe v zvezi z maso in hitrostjo udarne naprave
If the test has been conducted at a collision velocity higher than those prescribed in paragraphs 2.4.2 and 2.5.4 and/or with a mass greater than those prescribed in paragraphs 2.4.3 and 2.5.6, and the vehicle has met the requirements prescribed, the test shall be considered satisfactory.
Če je bil preskus opravljen pri hitrosti ob trku, ki je višja od hitrosti, predpisane v odstavkih 2.4.2 in 2.5.4, in/ali z maso, ki je večja od mase, predpisane v odstavkih 2.4.3 in 2.5.6, in je vozilo pri tem izpolnilo predpisane zahteve, se preskus šteje kot zadovoljiv.
The fuel tank shall be filled to at least 90 per cent of its capacity either with fuel or with a non-inflammable liquid having a density and a viscosity close to those of the fuel normally used.
Posoda za gorivo mora biti napolnjena vsaj do 90 odstotkov prostornine z gorivom ali nevnetljivo tekočino, katere gostota in viskoznost sta podobni gostoti in viskoznosti goriva, ki se običajno uporablja.
the technical service responsible for conducting the tests may allow the same vehicle as is used for tests prescribed by other Regulations (including tests capable of affecting its structure) to be used also for the tests prescribed by this Regulation; and
tehnična služba, pristojna za izvajanje preskusov, lahko dovoli uporabo istega vozila, ki se uporablja za preskuse, predpisane z drugimi pravilniki (vključno s preskusi, ki bi lahko vplivali na njegovo konstrukcijo), tudi za preskuse, predpisane s tem pravilnikom; in
The vehicle may be weighted to an extent not exceeding 10 per cent of its unladen kerb weight with additional weights rigidly secured to the structure in such a way as not to affect the behaviour of the structure of the passenger compartment during the test.
vozilo se lahko obteži z dodatnimi utežmi, ki ne smejo presegati 10 odstotkov mase neobremenjenega vozila in se togo pritrdijo na konstrukcijo, tako da med preskusom ne vplivajo na obnašanje konstrukcije potniškega prostora.
The instruments used to record the speed referred to in paragraphs 2.4.2 and 2.5.4 above shall be accurate to within one per cent.
Natančnost instrumentov za beleženje hitrosti iz odstavkov 2.4.2 in 2.5.4 mora biti do 1 %.
If a method other than that described in paragraph 2 above is used, its equivalence shall be demonstrated.
Če se uporabi drugačna metoda, kot je opisana v odstavku 2, je treba dokazati njeno enakovrednost.
TESTING OF FUEL TANKS MADE OF A PLASTIC MATERIAL
PRESKUŠANJE POSOD ZA GORIVO, IZDELANIH IZ PLASTIČNEGA MATERIALA
The tank shall be filled to its capacity with a water-glycol mixture or with another liquid having a low freezing point, which does not change the properties of the tank material, and shall then be subjected to a perforation test.
Posoda za gorivo se napolni do polne prostornine z mešanico vode in glikola ali drugo tekočino, ki ima nizko ledišče in ne spreminja lastnosti materiala posode za gorivo, nato pa se na posodi za gorivo opravi preskus s perforiranjem.
During this test the tank temperature shall be 233 K ± 2 K (– 40 °C ± 2 °C).
Med tem preskusom mora biti temperatura posode za gorivo 233 K ± 2 K (– 40 °C ± 2 °C).
The collision body shall be of steel and have the shape of a pyramid with equilateral-triangle faces and a square base, the summit and the edges being rounded to a radius of 3 mm.
Udarno telo za preskus s trkom mora biti jekleno in imeti obliko piramide, katere stranice imajo obliko enakostraničnih trikotnikov, osnovna ploskev pa je kvadrat, njen vrh in njeni robovi so zaobljeni s polmerom ukrivljenja 3 mm.
The centre of percussion of the pendulum shall coincide with the centre of gravity of the pyramid; its distance from the axis of rotation of the pendulum shall be 1 m.
Središče udarca nihala mora sovpadati s težiščem piramide; njegova razdalja od vrtilne osi nihala mora biti 1 m.
The total mass of the pendulum shall be 15 kg.
Skupna masa nihala mora biti 15 kg.
The energy of the pendulum at the moment of collision shall be not less than 30 Nm and as close to that value as possible.
Energija nihala v trenutku trka ne sme biti manjša od 30 Nm in mora biti čim bližje tej vrednosti.
The tests shall be made on the points of the tank which are regarded as vulnerable to frontal or rear collisions.
Preskusi se opravijo na točkah posode za gorivo, ki se štejejo za občutljive pri čelnem trku ali trku v zadnji del vozila.
The points regarded as vulnerable are those which are most exposed or weakest having regard to the shape of the tank or the way in which it is installed on the vehicle.
Za občutljive se štejejo tiste točke, ki so najbolj izpostavljene ali najšibkejše glede na obliko posode za gorivo oziroma način njene vgradnje na vozilu.
The points selected by the laboratories shall be indicated in the test report.
Točke, ki so jih izbrali preskuševalni laboratoriji, je treba navesti v poročilu o preskusu.
During the test, the tank shall be held in position by the fittings on the side or sides opposite the side of collision.
Med preskusom mora biti posoda za gorivo pritrjena na strani oziroma straneh, ki so na nasprotni strani glede na mesto trka.
No leak shall result from the test.
Preskus ne sme povzročiti iztekanja goriva.
At the choice of the manufacturer, all the impact tests may be carried out on one tank or each may be carried out on a different tank.
Po izbiri proizvajalca se lahko vsi preskusi trkov opravijo na eni posodi za gorivo ali pa se vsak preskus lahko opravi na drugi posodi za gorivo.
The tank and all its accessories shall be mounted onto a test fixture in a manner corresponding to the mode of installation on the vehicle for which the tank is intended or mounted in the vehicle itself or mounted in a test fixture made by a vehicle section.
Posoda za gorivo in ves pripadajoči pribor se pritrdita na preskuševalno ogrodje po postopku, ki ustreza načinu vgradnje na vozilo, za katerega je posoda za gorivo namenjena, ali pritrdita v vozilo samo ali pritrdita na preskuševalno ogrodje, ki ga izdela oddelek za vozila.
On request of the manufacturer and with the agreement of the Technical Service the tank may be tested without using any test fixture.
Na zahtevo proizvajalca in s soglasjem tehnične službe se lahko posoda preskusi brez uporabe kakršnega koli preskuševalnega ogrodja.
Water at 326 K (53 °C) shall be used as the testing fluid and shall fill the tank to its capacity.
Kot preskusna tekočina se uporabi voda pri temperaturi 326 K (53 °C), s katero se napolni posoda za gorivo do polne prostornine.
The tank shall be subjected to a relative internal pressure equal to double the working pressure and in any case to not less than 30 kPa at a temperature of 326 K ± 2 K (53 °C ± 2 °C) for a period of five hours.
Posoda za gorivo se za pet ur izpostavi relativnemu notranjemu tlaku, ki je enak dvojnemu delovnemu tlaku, vendar ni manjši od 30 kPa pri temperaturi 326 K ± 2 K (53 °C ± 2 °C).
During the test, the tank and its accessories shall not crack or leak; however, it may be permanently deformed.
Med preskusom posoda za gorivo in pripadajoči pribor ne smeta počiti ali puščati; vendar je dopustna trajna deformacija posode za gorivo.
The fuel used for the permeability test shall be either the reference fuel specified in Regulation No 83, Annex 9 or a commercial premium-grade fuel.
Gorivo, uporabljeno za preskus prepuščanja goriva, mora biti referenčno gorivo, določeno v Prilogi 9 k Pravilniku št. 83, ali pa komercialno gorivo super.
If the tank is only designed for installation on vehicles with a compression-ignition engine, the tank shall be filled with diesel fuel.
Če je posoda za gorivo zasnovana samo za vgradnjo na vozila z motorjem s kompresijskim vžigom, je treba posodo za gorivo napolniti z dizelskim gorivom.
Prior to the test, the tank shall be filled to 50 per cent of its capacity with testing fuel and stored, without being sealed, at an ambient temperature of 313 K ± 2 K (40 °C ± 2 °C) until the weight loss per unit time becomes constant, but for not more than four weeks (preliminary storage time).
Pred preskusom se posoda za gorivo napolni do 50 % njene prostornine s preskusnim gorivom in se odprta hrani pri temperaturi okolja 313 K ± 2 K (40 °C ± 2 °C), dokler izguba teže na časovno enoto ne postane konstantna, vendar ne več kot štiri tedne (začasno obdobje hranjenja).
The tank shall then be emptied and refilled to 50 per cent of its capacity with test fuel, after which it shall be hermetically sealed and be stored at a temperature of 313 K ± 2 K (40 °C ± 2 °C).
Nato se posoda za gorivo izprazni in ponovno napolni s preskusnim gorivom do 50 % prostornine, zatem pa nepredušno zapre in hrani pri temperaturi 313 K ± 2 K (40 °C ± 2 °C).
The pressure shall be adjusted when the contents of the tank have reached the testing temperature.
Tlak se nastavi, ko vsebina posode za gorivo doseže temperaturo preskušanja.
During the ensuing test period of eight weeks, the loss of weight due to diffusion during the test period shall be determined.
V naslednjem obdobju osmih tednov se meri izguba teže zaradi difuzije v obdobju preskušanja.
The maximum permissible average loss of fuel is 20 g per 24 hours of testing time.
Največja dovoljena povprečna izguba goriva je 20 g na 24 ur časa preskušanja.
If the loss due to diffusion exceeds the value indicated in paragraph 3.3, the test described there shall be carried out again, on the same tank, to determine the loss by diffusion at 296 K ± 2 K (23 °C ± 2 °C) but under the same conditions otherwise.
Če je izguba zaradi difuzije večja od vrednosti iz odstavka 3.3, se preskus, opisan v navedenem odstavku, ponovi na isti posodi za gorivo, da se določi izguba, povzročena z difuzijo pri temperaturi 296 K ± 2 K (23 °C ± 2 °C), vendar pod istimi pogoji.
After the test referred to in paragraph 3, the tank shall still meet the requirements set out in paragraphs 1 and 2.
Po preskusu iz odstavka 3 mora posoda za gorivo še vedno izpolnjevati zahteve iz odstavkov 1 in 2.
RESISTANCE TO FIRE
POŽARNA ODPORNOST
There shall be no leakage of liquid fuel from the tank.
To ne sme povzročiti iztekanja tekočega goriva iz posode za gorivo.
Three tests shall be made on different tanks filled with fuel as follows:
Na različnih napolnjenih posodah za gorivo se opravijo trije preskusi:
If the tank is designed for installation on vehicles equipped with either a positive ignition engine or a compression ignition engine, three tests shall be carried out with tanks filled with premium-grade gasoline;
če je posoda za gorivo namenjena vgradnji v vozila z motorjem s prisilnim vžigom ali motorjem s kompresijskim vžigom, se opravijo trije preskusi na posodah za gorivo, napolnjenih z gorivom super;
If the tank is only designed for installation on vehicles equipped with a compression-ignition engine, three tests shall be carried out with tanks filled with diesel fuel;
če je posoda za gorivo namenjena samo vgradnji v vozila z motorjem s kompresijskim vžigom, se opravijo trije preskusi na posodah za gorivo, napolnjenih z dizelskim gorivom;
For each test, the tank and its accessories shall be installed in a testing fixture simulating actual mounting conditions as far as possible.
pri vsakem preskusu so posoda za gorivo in pripadajoči pribor pritrjeni na preskuševalno ogrodje tako, da so čim bolj simulirani pogoji dejanske vgradnje.
The method whereby the tank is fixed in the fixture shall correspond to the relevant specifications for its installation.
Način pritrditve posode za gorivo na preskuševalnem ogrodju mora ustrezati ustreznim specifikacijam za njeno vgradnjo.
In the case of tanks designed for a specific vehicle use, vehicle parts which protect the tank and its accessories against exposure to flame or which affect the course of the fire in any way, as well as specified components installed on the tank and plugs shall be taken into consideration.
Pri posodah za gorivo, ki so zasnovane za uporabo v določenih vozilih, se upoštevajo deli vozila, ki posodo za gorivo in njen pribor ščitijo pred izpostavitvijo plamenu ali na kakršen koli način vplivajo na širitev ognja, in tudi posebni sestavni deli, ki so vgrajeni na posodi za gorivo, ter vijaki na pokrovu.
All openings shall be closed during the test, but venting systems shall remain operative.
Med preskusom morajo biti vse odprtine zaprte, zračniki pa morajo delovati še naprej.
The flame to which the tank is exposed shall be obtained by burning commercial fuel for positive-ignition engines (hereafter called ‘fuel’) in a pan.
Plamen, ki mu je izpostavljena posoda za gorivo, se dobi s sežiganjem komercialnega goriva za motorje s prisilnim vžigom (v nadaljnjem besedilu: gorivo) v ponvi.
The quantity of fuel poured into the pan shall be sufficient to permit the flame, under free-burning conditions, to burn for the whole test procedure.
Količina goriva v ponvi mora biti takšna, da plamen v pogojih prostega gorenja gori skozi celoten preskusni postopek.
The pan shall therefore exceed the horizontal projection of the tank by at least 20 cm, but not more than 50 cm.
Ponev skladno s tem presega vodoravno projekcijo posode za gorivo za najmanj 20 cm in največ 50 cm.
The sidewalls of the pan shall not project more than 8 cm above the level of the fuel at the start of the test.
Bočne stene ponve lahko segajo največ 8 cm nad nivo goriva na začetku preskusa.
The pan filled with fuel shall be placed under the tank in such a way that the distance between the level of the fuel in the pan and the tank bottom corresponds to the design height of the tank above the road surface at the unladen mass (see paragraph 7.4).
Ponev, napolnjena z gorivom, se postavi pod posodo za gorivo tako, da razdalja med nivojem goriva v ponvi in dnom posode za gorivo ustreza konstrukcijsko določeni višini posode za gorivo nad površino ceste pri masi neobremenjenega vozila (glej odstavek 7.4).
Either the pan, or the testing fixture, or both, shall be freely movable.
Ponev ali preskuševalno ogrodje ali oboje je mogoče prosto premikati.
During phase C of the test, the pan shall be covered by a screen placed 3 cm ± 1 cm above the fuel level.
Med fazo C preskusa se ponev na višini 3 cm ± 1 cm nad nivojem goriva pokrije z zaslonom.
The screen shall be made of a refractory material, as prescribed in Appendix 2.
Zaslon mora biti iz ognjevzdržnega materiala, kot je predpisano v Dodatku 2.
There shall be no gap between the bricks and they shall be supported over the fuel pan in such a manner that the holes in the bricks are not obstructed.
Med opekami ni reže, nad ponvijo z gorivom pa so nameščene tako, da so odprtine v njih proste.
The length and width of the frame shall be 2 cm to 4 cm smaller than the interior dimensions of the pan so that a gap of 1 cm to 2 cm exists between the frame and the wall of the pan to allow ventilation.
Dolžina in širina okvira sta od 2 cm do 4 cm manjši od notranjih mer ponve, tako da med okvirom in bočno steno ponve nastane reža za prezračevanje širine 1 cm do 2 cm.
When the tests are carried out in the open air, sufficient wind protection shall be provided and the wind velocity at fuel-pan level shall not exceed 2,5 km/h.
Pri izvajanju preskusov na prostem se zagotovi zadostna zaščita pred vetrom in hitrost vetra v višini ponve z gorivom ni večja od 2,5 km/h.
Before the test the screen shall be heated to 308 K ± 5 K (35 °C ± 5 °C).
Pred preskusom se zaslon ogreje na temperaturo 308 K ± 5 K (35 °C ± 5 °C).
The firebricks may be wetted in order to guarantee the same test conditions for each successive test.
Šamotna opeka se lahko navlaži, da se zagotovijo enaki pogoji za vsak naslednji preskus.
Phase A: Pre-heating (Figure 1)
Faza A: predgrevanje (slika 1)
Phase B: Direct exposure to flame (Figure 2)
Faza B: neposredna izpostavljenost plamenu (slika 2)
For 60 seconds the tank shall be exposed to the flame from the freely burning fuel.
Posoda za gorivo se izpostavi plamenu prosto gorečega goriva za 60 sekund.
Phase C: Indirect exposure to flame (Figure 3)
Faza C: posredna izpostavljenost plamenu (slika 3)
As soon as phase B has been completed, the screen shall be placed between the burning pan and the tank.
Takoj po končani fazi B se med ponev z gorečim gorivom in posodo za gorivo namesti zaslon.
The tank shall be exposed to this reduced flame for a further 60 seconds.
Posoda za gorivo se izpostavi tako zmanjšanemu plamenu za nadaljnjih 60 sekund.
Phase D: End of test (Figure 4)
Faza D: konec preskusa (slika 4)
The burning pan covered with the screen shall be moved back to its original position (phase A).
Ponev z gorečim gorivom, pokrita z zaslonom, se premakne v prvotni položaj (faza A).
The fixture used for the test shall match the manner of installation of the tank on the vehicle, including the way in which the tank vent works.
Preskuševalno ogrodje, ki se uporabi za preskus, mora ustrezati vgradnji posode za gorivo v vozilu, vključno z načinom delovanja prezračevanja posode za gorivo.
The tank filled to 50 per cent of its capacity with water at 293 K (20 °C) shall be subjected for one hour to an ambient temperature of 368 K ± 2 K (95 °C ± 2 °C).
Posoda za gorivo, napolnjena do 50 % prostornine z vodo s temperaturo 293 K (20 °C), mora biti eno uro izpostavljena temperaturi okolja 368 K ± 2 K (95 °C ± 2 °C).
The results of the test shall be considered satisfactory if, after the test, the tank is not leaking or seriously deformed.
Rezultati preskusa se štejejo za zadovoljive, če po preskusu posoda za gorivo ne prepušča ali ni bistveno deformirana.
The trade name or mark shall be affixed to the tank; it shall be indelible and clearly legible on the tank when the latter is installed on the vehicle.
Na posodi za gorivo je nameščeno blagovno ime ali znamka, ki je neizbrisno in jasno čitljivo tudi po vgradnji posode za gorivo v vozilo.
TEST OF RESISTANCE TO FIRE
PRESKUS ODPORNOSTI PROTI OGNJU
Phase A: Pre-heating
Faza A: predgrevanje
Fuel pan with burning fuel
Ponev za gorivo z gorečim gorivom
Testing fixture
Preskuševalno ogrodje
Phase B: Direct exposure to flame
Faza B: neposredna izpostavljenost plamenu
Sheet-metal pan
Pločevinasta ponev
Phase C: Indirect exposure to the flame
Faza C: posredna izpostavljenost plamenu
Phase D: End of test
Faza D: konec preskusa
DIMENSIONS AND TECHNICAL DATA OF FIREBRICKS
MERE IN TEHNIČNI PODATKI ZA ŠAMOTNO OPEKO
(Dimensions are in mm)
(Mere so v mm)
15 radius
6 izsekov
6 cutouts
polmera 15
30 diameter
15 lukenj
15 holes
premera 30
Fire resistance (Seger-Kegel) SK 30
Odpornost proti ognju (Seger-Kegel) SK 30
Regulation No 44 of the Economic Commission for Europe of the United Nations (UNECE) — Uniform provisions concerning the approval of restraining devices for child occupants of power-driven vehicles (‘Child Restraint Systems’) [2016/1722]
Vključuje vsa veljavna besedila do:
Incorporating all valid text up to:
Dopolnila 10 sprememb 04 – začetek veljavnosti: 18. junij 2016
Supplement 10 to the 04 series of amendments — Date of entry into force: 18 June 2016
VSEBINA
Approval
Splošne specifikacije
General specifications
Posebne specifikacije
Particular specifications
Opis preskusov
Description of tests
Poročilo o homologacijskem preskusu in ustreznosti proizvodnje
Test reports of type approval and of production qualification
Spremembe in razširitev homologacije tipa sistema za zadrževanje otrok
Modifications and extension of approval of a type of child restraint system
Ustreznost proizvodnje
Production qualification
Skladnost proizvodnje in rutinski preskusi
Conformity of production and routine tests
Kazni za neskladnost proizvodnje
Production definitively discontinued
Navodila
Instructions
Nazivi in naslovi tehničnih služb, ki izvajajo homologacijske preskuse, in homologacijskih organov
Names and addresses of Technical Services responsible for conducting approval tests and of Type Approval Authorities
Prehodne določbe
Transitional provisions
PRILOGE
ANNEXES
1 Sporočilo
1 Communication
2 Namestitev homologacijskih oznak
2 Arrangements of the approval marks
3 Preskuševalna naprava za preskus odpornosti proti prahu
3 Arrangement of apparatus for dust resistance test
4 Korozijski preskus
4 Corrosion test
5 Preskus odrgnjenja in mikrozdrsa
5 Abrasion and microslip test
6 Opis preskusnega vozička
6 Description of trolley
7 Krivulja pojemka ali pospeška preskusnega vozička kot funkcije časa
7 Curve of trolley's deceleration or acceleration, as function of time
8 Opis preskusnih lutk
8 Description of manikins
9 Preskus čelnega trčenja ob oviro
9 Frontal impact test against a barrier
10 Preskusni postopek pri trčenju od zadaj
10 Rear impact test procedure
11 Dodatna pritrdišča, potrebna za pritrditev sistemov za zadrževanje otrok „poluniverzalne“ kategorije v motornih vozilih
11 Additional anchorages required for attaching child restraints in the semi-universal category to motor vehicles
12 Sedež
12 Chair
13 Standardni varnostni pas
13 Standard safety belt
14 Homologacijska shema (shematski prikaz iso 9002:2000)
14 Type approval scheme (flow chart iso 9002:2000)
15 Pojasnila
15 Explanatory notes
16 Nadzor skladnosti proizvodnje
16 Control of conformity of production
17 Preskus materiala, ki absorbira energijo
17 Test of energy absorbing material
18 Metoda določanja območja udarca na modelu glave pri napravah za zadrževanje otrok s hrbtnim naslonom in za določanje najmanjše velikosti bočnih kril pri nazaj obrnjenih napravah