Abstract: Aspects relate to calculating energy expenditure values from an apparatus configured to be worn on an appendage of a user. Steps counts may be quantified, such as by detecting arm swings peaks and bounce peaks in motion data. A search range of acceleration frequencies related to an expected activity may be established. Frequencies of acceleration data within a search range may be analyzed to identify one or more peaks, such as a bounce peak and an arm swing peak. Novel systems and methods may determine whether to utilize the arm swing data, bounce data, and/or other data or portions of data to quantify steps. The number of peaks (and types of peaks) may be used to choose a step frequency and step magnitude. At least a portion of the motion data may be classified into an activity category based upon the quantification of steps.

Abstract: Methods for the preparation of a tellurium or selenium compound of formula Ra M Rb wherein M is tellurium or selenium and Ra and Rb are different C.sub.1-20 alkyl, alkenyl or aryl groups are provided in which a compound of formula (Ra).sub.2 M.sub.2 is reacted with a compound of formula (Rb).sub.2 M in each compound M being the same. Compounds of formula RaMMRb may also be isolated as an intermediate. Ra M Rb compounds are useful as precursors for metal organic vapor phase epitaxy processes.

Abstract: Tellurium and selenium alkyls are purified by thermal dissociation of the adduct of the compound with a Group IB or IIB metal.

Abstract: Tellurium and selenium dialkyls are prepared by reacting the corresponding tetrahalide with a Group I metal alkyl.

Abstract: A method of growing an epitaxial crystalline layer on a substrate which comprises the steps of(a) providing in the reaction zone of a reaction vessel a heated substrate(b) establishing a gas stream, provided by a carrier gas which gas stream comprises at least 50% by volume of a gas which suppresses the homogeneous nucleation of particles in the vapor phase which contains, in the vapor phase, at least one alkyl of an element selected from Group 15 and Group 16 of the Periodic Table,(c) passing the gas stream through the reaction zone into contact with the heated substrate, and(d) irradiating at least a major part of the surface of the substrate with electromagnetic radiation to provide photolytic decomposition of the at least one alkyl and consequential epitaxial deposition of the layer containing the said element across at least a major part of the surface of the substrate.

Abstract: A method of preparing high purity dimethyl cadmium or dimethyl zinc suitable for use in the deposition of Group II-VI epitaxial layers, which consists of forming an adduct of the metal alkyl with a non-chelating tertiary amine containing at least two tertiary amino groups per amine molecule, and subsequently dissociating the adduct to liberate the metal alkyl as a vapor. The adducts formed during the preparative method are found to dissociate readily on heating and yet are substantially involatile and so do not contaminate the liberated metal alkyl. A preferred amine suitable for use in the preparative method is 4,4' bipyridyl.

Abstract: A layer of Cd.sub.x Hg.sub.1-x Te is grown on the surface of a substrate by decomposing alkyls of cadmium and telluride in a mercury atmosphere. The substrate is placed in a vessel containing a mercury bath with the vessel and bath at a suitable pressure and a temperature below the alkyl decomposition temperature. Hydrogen is passed through bubblers separately containing alkyls of cadmium, telluride and, if required, a dopant into the vessel. The substrate is independently heated above the temperature of the vessel so that the alkyls decompose on the substrate. The substrate may be CdTe, a II-VI compound or mixed II-VI alloy. The alkyls may be dimethyl cadmium, diethyl cadmium, dipropyl cadmium, dimethyl telluride, diethyl telluride, dipropyl telluride, dibutyl telluride etc., or hydrogen substituted tellurium alkyls such as hydrogen ethyl telluride etc.

Abstract: A method of producing a trialkyl gallium compound (R.sub.A).sub.3 Ga, where R.sub.A is selected from methyl and ethyl, includes the step of reacting a gallium trihalide with a Grignard reagent of formula R.sub.A Mg Q, where Q is a halogen, the reaction being carried out in the presence of an ether of the formula R.sub.1 R.sub.2 O having a boiling point at least 50 Celsius degrees above that of the trialkyl gallium compound (R.sub.A).sub.3 Ga, wherein R.sub.1 and R.sub.2 are organic radicals at least one of which has at least 5 carbon atoms.The organic radicals R.sub.1 and R.sub.2 may be aromatic and/or aliphatic radicals. They are preferably alkyl or phenyl radicals. Preferably R.sub.1 R.sub.2 O is an ether having a boiling point more than 100.degree. C. above that of the trialkyl gallium compound. The radicals R.sub.1 and R.sub.2 may each independently have from 1 to 14 carbon atoms but preferably together R.sub.1 and R.sub.2 have between seven and twelve carbon atoms inclusive.Desirably, R.sub.1 R.sub.

Abstract: A method of producing an adduct of an organometallic compound M(R.sup.1).sub.3 where M is either indium or gallium and (R.sup.1).sub.3 represents a plurality of organic radicals which may be the same or different, preferably methyl or ethyl groups, comprising electrolysing, using a sacrificial anode of the metal M, a solution containing components 1 and 2 as follows:component 1: one or more organomagnesium halide compounds R.sup.1 MgX where X is a halide radical selected from Cl, Br and I; where R.sup.1 represents one of the groups contained in (R.sup.1).sub.3 ;component 2: a polar aprotic liquid which is a solvent for component 1, e.g. tetrahydrofuran, diethyl ether, di-isopentyl ether, di-n-butyl ether, diphenyl ether or anisole.Preferably, the solution electrolysed additionally contains a third component, component 3, which is one or more organic halides R.sup.1 X.sub.A, where R.sup.1 is one of the groups contained in (R.sup.1).sub.3, X.sub.

Abstract: A layer of Cd.sub.x Hg.sub.1-x Te is grown on a substrate by growing layers of HgTe t.sub.1 thick, and CdTe t.sub.2 thick alternately. The thicknesses t.sub.1 and t.sub.2 combined are less than 0.5 .mu.m so that interdiffusion occurs during growth to give a single layer of Cd.sub.x Hg.sub.1-x Te. The HgTe layers are grown by flowing a Te alkyl into a vessel containing the substrate and filled with an Hg atmosphere by an Hg bath. The CdTe layers are grown by flowing of Cd alkyl into the vessel where it combines preferentially with the Te on the substrate. Varying the ratio of t.sub.1 to t.sub.2 varies the value of x. Dopants such as alkyls or hydrides of Al, Ga, As and P, or Si, Ge, As and P respectively may be introduced to dope the growing layer.

Abstract: A method of producing an adduct of an organometallic compound M.sup.1 (R.sup.1).sub.x, where M.sup.1 is a Group II or Group III metallic element and R.sup.1).sub.x represents a plurality of organic radicals, which may be the same or different, x being an integer equal to the valency of M.sup.1, comprises electrolysing, using a sacrificial anode of the metal M.sup.1, a solution containing components A, B and C as follows:A: a magnesium compound MgR.sub.2.sup.1 ;B: a readily ionizable support electrolyte providing relatively large anions and cations;C: a polar aprotic liquid which is a solvent for both components A and B; the metal M.sup.1 being selected from the group consisting of: indium, gallium, cadmium.

Abstract: An inexpensive and reliable security bar that may be easily and quickly assembled between structural supports of a guarded area to prevent entry into the area. The present security bar comprises first and second elongated bar members, one end of each of which is respectively installed into a structural support. The security bar members are substantially aligned with one another across the entrance to the guarded area, so that a small gap is formed between the second ends thereof. A hollow coupling sleeve is positioned over the gap, and a dowel or pin is inserted through a hole in the sleeve and into the gap between the bar members. Accordingly, when in the assembled relationship, the sleeve and pin cooperate to inhibit the lateral and angular displacement of the bar members, whereby to prevent removal of the security bar from the guarded area after installation between the structural supports thereof.