Vehicle vibration exposure has been linked to chronic back pain and low-back symptoms among agricultural tractor drivers. The objectives of this study by the National Institute for Occupational Safety and Health (NIOSH) were to assess driver whole-body vibration (WBV) exposures and recommend interventions to reduce the risk of back-related injuries, particularly relative to vehicle jarring/jolting (the transient mechanical shock components of WBV). The methodology included collecting, from two independent samples, field data and health and work history data of farm equipment operators. Data were collected during mowing, raking, baling, chiseling, tilling, and road travel for different model tractors. Spraying using a sprayer and shrub removal with a skid-steer loader were also included. Based on ISO 2631 (1985), the American Conference of Governmental Industrial Hygienists, threshold limit values, presents 0.5 m/s2 as the action level recommended by the Commission of European Communities for overall weighted total RMS acceleration (vector sum for axes x, y, and z) [ACGIH, 2006. Threshold limit values and biological exposure indices. Cincinnati, OH]. WBV measured at the operator/seat interface exceeded this action level. The roughest rides and highest vector sum accelerations occurred with small utility tractor mowers (3.3 and 2.8 m/s2) and a skid-steer loader (1.7 m/s2). Major findings from health and work history data showed 96% of participants reported having to bend or twist their necks, although 24% reported neck symptoms. Sixty-four percent of participating operators reported experiencing back symptoms (e.g., pain, aching, stiffness, etc.). Recommendations included: specifying a seat that "better" isolates operators from jars/jolts with new tractor purchases; maintaining the seat/seat suspension and replacing worn or damaged cushions with NIOSH tested viscoelastic foam padding; using larger diameter tires with radial-ply instead of bias-ply construction, particularly on small utility tractor-mowers, to aid in attenuating ride "roughness"; using a swivel seat to reduce the stress on the neck from bending or twisting; and improving efforts to educate owner/operators of the adverse effects of WBV exposures. Since the data presented in this paper were collected from two independent samples, the authors were unable to draw any correlations or etiological inferences from the study. However, results were compared and contrasted with other studies which included similar vibration measurements in agriculture.
Gaia Vince's new book delivers a message that is clear, sharp and jolting. Large regions of the world are becoming unlivable, she says - lethal for 3 to 5 billion of us. We can survive, but to do so will require a planned and deliberate migration of the kind humanity has never before undertaken. Her new book, "Nomad Century: How Climate Migration Will Reshape Our World" - Gaia Vince, the award-winning science journalist joins us now from London. Thanks for being with us.
jolting
The key is doing a high-impact activity that will stress the bone, she added. "Swimming and bicycling, while you can get a great cardiovascular workout, you're not going to get that weight-bearing force and jolting impact that builds bone."
Jolting surge doesn't provoke. AUC.register('auc_MessageboardPostRowDisplay'); AjaxBusy.register('masked', 'busy', 'auc_MessageboardPostRowDisplay', null, null) S. J. Digriz Sep 7, 2017, 04:59 pm 1 person marked this as a favorite. Note that with jolting surge you have to be right up next to some bad thing, and if you count the chance of missing (about 50% for a 1st level technomancer targeting a non-minion bad thing), the expected damage per spell is about 7 points electrical. Magic missile, also a 1st level spell, has a 0% chance of missing, and so its expected damage per spell is 10.5, and you can cast it while far away from the bad thing. I'd go magic missile over jolting surge.
Note that with jolting surge you have to be right up next to some bad thing, and if you count the chance of missing (about 50% for a 1st level technomancer targeting a non-minion bad thing), the expected damage per spell is about 7 points electrical. Magic missile, also a 1st level spell, has a 0% chance of missing, and so its expected damage per spell is 10.5, and you can cast it while far away from the bad thing. I'd go magic missile over jolting surge.
Used to compact cement mortar prisms 40x40x160 mm in the three gang mould. The apparatus consists of a table holding the mould, seated on a rotating cam driven at 60 revolutions per minute.The jolting group is connected to the table by bayonet joints for quick checking of the weights. The drop height (15,0 mm) is adjustable to keep it correct also after intensive uses. The apparatus is supplied with separate control panel including main switch, automatic digital drop counter, start/stop push button.
The empty mould, along with the feed hopper is placed on the table of the jolting table and secured by two fast-action articulated grips. The table surface is properly machined to ensure perfect contact with the base surface of the mould.
The voltage-gated sodium channel Scn8a is broadly distributed in brain and spinal cord. We have identified a missense mutation in Scn8a that is associated with cerebellar ataxia in the jolting mutant, a mild allele of the "motor endplate disease" locus. The jolting mutation results in substitution of Thr for an evolutionarily conserved Ala residue in the cytoplasmic S4-S5 linker of domain III. Introduction of the corresponding mutation into the rat brain IIA sodium channel shifted the voltage dependence of activation by 14 mV in the depolarizing direction, without affecting the kinetics of fast inactivation or recovery from inactivation. A shift in the threshold of the Scn8a channel could account for the reduced spontaneous activity of Purkinje cells, reduced inhibitory output from the cerebellum, and loss of motor control observed in jolting mice.
Great story! I'm sure the chair gave 'inner core strength'- the modern version of what we are all told we need. My guess is that the handles on either side are what did the jolting. The wind up underneath was to make the spring longer or shorter - so the violence ( or excitement) of the jolting greater or less. The modern equivalent is a giant ball to sit on. 2ff7e9595c
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