This paper presents experimental techniques to determine the amount of lubricant in each of the major components of an R134a automotive A/C system using ND-8 (PAG 46) oil—compressor, condenser, liquid tube, evaporator and accumulator. Three different techniques are presented: Remove and weigh Flushing Mix and sample The advantages and disadvantages, as well as the suitability of each technique ...

Within the idealized scheme of a 1-dimensional Frenkel-Kontorova-like model, a special “quantized” sliding state was found for a solid lubricant confined between two periodic layers [1]. This state, characterized by a nontrivial geometrically fixed ratio of the mean lubricant drift velocity 〈vcm〉 and the externally imposed translational velocity vext, was understood as due to the kinks (or soli...

Operational discharges of hydrocarbons from maritime activities can have major cumulative impacts on marine ecosystems. Small quantities of oil (i.e., 10 ml) results in often lethally reduced thermoregulation in seabirds. Thin sheens of oil and drilling fluids form around offshore petroleum production structures from currently permissible operational discharges of hydrocarbons. Methodology was ...

Ester liquids are environmentally friendly insulating oils, and they can be used as an alternative to mineral oil in transformers, even though most countries spills of ester oils must treated like oil. Furthermore, the breakdown characteristics worse than those heterogeneous electric fields. In this paper, we present a comprehensive experimental research on both positive negative lightning impu...

Penicillin G acylase from E. coli TA1 was immobilized by Cross-Linked Enzyme Aggregates (CLEA), a new method for immobilization. This biocatalyst and commercial immobilized penicillin G acylase (PGA-450) were used to study the effect of pH, temperature and substrate concentration on the synthesis of ampicillin from phenyl glycine methyl ester (PGME) and 6-aminopenicillanic acid (6-APA). Compare...

OBJECTIVE To assess the influence of an isotonic lubricant used during sperm sample collection on [1] ease of collection and [2] resultant sperm quality. DESIGN Paired randomized cross-over design. SETTING Tertiary hospital. DONOR(S) Healthy men over 18 years old with normal semen analysis as per World Health Organization 2010 guidelines. INTERVENTION(S) Collection of semen sample from ...

Penicillin G acylase from E. coli TA1 was immobilized by Cross-Linked Enzyme Aggregates (CLEA), a new method for immobilization. This biocatalyst and commercial immobilized penicillin G acylase (PGA-450) were used to study the effect of pH, temperature and substrate concentration on the synthesis of ampicillin from phenyl glycine methyl ester (PGME) and 6-aminopenicillanic acid (6-APA). Compare...

The total synthesis and evaluation of a key systematic series of vinblastines that incorporate the first deep-seated changes to the substituent at C4 are detailed. The synthetic approach features an expanded and redefined scope of a 1,3,4-oxadiazole [4 + 2]/[3 + 2] cycloaddition cascade in which electronically mismatched electron-deficient trisubstituted alkenes and unactivated trisubstituted a...

The synthesis and spectroscopic characterization of three five-coordinate nitrosyliron(II) complexes, [Fe(Porph)(NO)], are reported. These three nitrosyl derivatives, where Porph represents protoporphyrin IX dimethyl ester, mesoporphyrin IX dimethyl ester, or deuteroporphyrin IX dimethyl ester, display notable differences in their properties relative to the symmetrical synthetic porphyrins such...