Journal Articles

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Application of resource dependency theory and transaction cost theory in analysing outsourcing information communication services decisions: A case of selected public university libraries in Kenya
(Emerald Group Publishing Limited, 1983) Kiplang’at, Joseph; Gichoya, David; Mwai, Naomi Wangari
Purpose – The aim of this paper is to establish how resource dependency theory (RDT) and transaction cost theory (TCT) can inform decisions to outsource ICT services by public university libraries in Kenya. Design/methodology/approach – The study adopted a multiple case study strategy in four selected public universities libraries in Kenya. Purposive sampling was used to identify respondents and data collection was done using a semi-structured interview schedule. Findings – The study highlights how RDT and TCT theoretical perspectives illuminate some of the reasons, and problems associated with Information and Communications Technology outsourcing in Libraries. The paper concludes with recommendations and the way forward. Research limitations/implications – The study was limited to the outsourcing of information technology services in four public university libraries in Kenya, namely, Kenyatta University (KU) in Kahawa, Nairobi; Moi University (MU) in Eldoret; University of Nairobi (UON) in Nairobi; and Jomo Kenyatta University of Agriculture and Technology (JKUAT) in Juja, Thika. This being a qualitative study (and taking into consideration the subjective views where bias could occur), the researchers ensured that the research was reliable by recording and taking notes during the interviews and by using peer-debriefing and professionals in the field to ascertain their views. Practical implications – The paper provides practical insights into outsourcing of Information Technology (IT) services in Public University libraries and information centres in Kenya. This study is useful for university libraries, information professionals, information communication technology professionals and university management. Social implications – The implications of the study are that outsourcing needs to be guided by clear policies that are documented and communicated to all the stakeholders. Originality/value – This research assesses IT outsourcing services in selected public academic libraries in Kenya
Development of a remote sensing methodology for analyzing shifting cultivation and grazing patterns in the semi-arid region of Kenya.
(1983) Wayumba, GO
On outlier identification in geodetic networks using principal component analysis
(1986) Aduol, Francis O.
Detection of outliers in geodetic networks using principal component analysis and bias parameter estimation.
(1987) Aduol, Francis O.
Temperature dependence of the Hg 6s6p(3P0→3P1) transition induced by nitrogen
(Elsevier, 1987) Callear, Anthony B; Shiundu, Paul M
The rate coefficient of the process Hg 6s6p(3P0→3P1) induced by nitrogen collisions has been measured over the range 285 to 340 K. The temperature variation closely matches that of the concentration of N2(v = 1). The results support the electronic to vibrational energy-transfer mechanism for the deactivation of 3P1 to 3P0 by nitrogen.
Efforts to identify early spontaneous embryo mortality in the rhesus monkey (Macaca mulatta)
(1989) Mbai, Fiona N
Computer-controlled apparatus for automated development of continuous flow methods
(1989) Wentzell, Peter D; Hatton, Michael J; Shiundu, Paul M; Ree, Ronald M; Wade, Adrian P
An automated apparatus to assist in the development ofanalytical continuous flow methods is described. The system is capable of controlling and monitoring a variety ofpumps, valves, and detectors through an IBM PC-AT compatible computer. System components consist of two types ofperistaltic pumps (including a multiplepump unit), syringepumps, electrically andpneumatically actuated valves, and an assortment of spectrophotometric and electrochemical detectors. Details ofthe interface circuitry are given where appropriate. To demonstrate the utility of the system, an automatically generated response surface is presentedfor theflow injection determination of iron(II) by its reaction with 1,10-phenanthroline.
Spectrophotometric determination of peroxydisulphate with o-dianisidine by flow injection
(1990) Shiundu, Paul M; Wade, Adrian P; Jonnalagadda, S. B
Precise and accurate knowledge of peroxydisulfate ion concentration is critical in industrial polymer production, where it is extensively used as an activator. Its ability to oxidize in either acidic, neutral, or alkali media also makes it widely applicable in many other areas of chemistry.In this paper we present an optimized spectrophotometric flow injection method for determination of peroxydisulfate. The analyte oxidizes o-dianisidine to form a stable product which has a convenient absorbance maximum at 450 nm. This provides a simple and sensitive alternative to present methods which are more costly, tedious, or complex. Keywords: spectrophotometric method, peroxydisulphate
Spectrophotometric determination of palladium with sulfochlorophenolazorhodanine by flow injection
(1990) Shiundu, Paul M; Wentzell, Peter D; Wade, Adrian P
Sulfochlorophenolazorhodanine (as its sodium salt) has been used in the automated development of a sensitive flow-injection procedure for the spectrophotometric determination of palladium. The resulting method has high sample throughput, good precision, and low consumption of both sample and reagents. The optimum pH for the reaction is 5.0 and the response is constant at pH between 4.7 and 5.3. The sensitivity (calibration slope) of the procedure is 4.4 × 103 l./mole. The linear dynamic range is 0.045–30.0 μg/ml. The sample throughput is at least 120/hr. An automated procedure for optimization of analytical variables is described and a two-variable response surface for the system is given. Interference studies on 19 metal ions show that the method has good selectivity.
Automated exploration and exploitation of flow-injection response surfaces
(Elsevier, 1990) Wadell, A.P; Shiundu, P.M; Wentze, P.D
Three-dimensional plots of instrumental responses vs. chemical concentrations or flow parameters have been 1 obtained in an automated manner on a computer-controlled flow-injection methods development system. Consideration of several alternative responses for flow-injection systems is shown to help characterize a chemistry more thoroughly and reveal the best experimental conditions. One may see the effects of individual experimental variables (reagent concentrations, pH, flow-rates, etc.), the interactions of these variables, instrumental factors and limitations of the surface exploration procedure employed. Chemical systems studied were the photometric determination of phosphate, palladium(II), iron(II) and persulfate. The propriety of automated response surface mapping is demonstrated and the efficacies of simplex and grid search approaches to response surface exploration are contrasted. Responses obtained include absorbance at peak maximum, relative standard deviation of maximum absorbance, time from injection to peak maximum and wavelength of maximum absorbance. Higher dimensional response surface representations of peak shape and absorbance spectra are also presented. The results show that the response chosen governs the general shape of the surface and the height at any point. This approach to automated characterization of chemical reactions in flow analysis is critically assessed
Auto-resonant peniotron amplifier with a down tapered DC magnetic field
(Taylor & Francis, 1990-02) Musyoki, Stephen; Yokoo, Kuniyoshi; Sato, Nabuyi; Ono, Shoichi
High efficiency operation of an auto-resonant peniotron amplifier operating with a down tapered DC magnetic field is discussed and the basic design concepts for a 200 GHz experimental prototype tube are described.
Development of catalytic photometric flow injection methods for the determination of selenium
(1991) Shiundu, Paul M; Wade, Adrian P
Versatile IEEE-488 data acquisition and control routines for a diode array spectrophotometer
(1991) Shiundu, Paul M; Wade, Adrian P
The UV-visible diode array spectrophotometer is a work-horse instrument for many laboratories. This article provides simple data acquisition and control routines in Microsoft QuickBasic for a HP-8452A diode array spectrophotometer interfaced to an IBM PC/XT/AT, or compatible, microcomputer. These allow capture of full spectra and measure absorbance at one or several wavelengths at preset time intervals. The variance in absorbance at each wavelength is available as an option.
Auto-resonant eniotron oscillator using a magnetron type cavity
(1991) Musyoki, Stephen; Yokoo, Kuniyoshi; Sato, Nobuyuki; Ono, Shoichi
In an ideal auto-resonant eniotron oscillator (ARPO), all the electrons are able to give almost all their kinetic energy to an electromagnetic wave, resulting in a conversion efficiency of nearly 100%. However, the electric field strength required to drive a highly efficient interaction is difficult to achieve in an ordinary rectangular or circular waveguide cavity because of the low interaction coupling between electrons and the electromagnetic wave in the cavity. In this aper, we describe our investigation of an ARPO with a magnetron type cavity in lace of that above. In this cavity, the coupling becomes sufficiently strong to confirm experimentally the romising features of an ARPO. Additionally, the experiments should be useful for developing highly efficient medium-power oscillators in the microwave region. Here we resent our rocedure for designing such an experimental tube and our computer simulation results for its operational characteristics
Design of a high power, 10 GHz auto-resonant peniotron amplifier
(1992) Musyoki, Stephen; Sakamoto, Keishi; Watanabe, Akihiko
The autoresonant peniotron amplifier is a suitable source of high power RF radiation because of its high gain, high power, high frequency and high efficiency operation features. In this report we present our simulation results of a 10 GHz, 2.2 GW autoresonant peniotron amplifier with an electron energy conversion efficiency of 72.5 % and a gain of about 58 dB
Spectrophotometric method for determination of sulfide with iron (III) and nitrilotriacetic acid by flow injection
(Elsevier, 1992) Kester, Michael D; Shiundu, Paul M; Wade, Adrian P.
A manual colorimetric method for determination of sulfide has been adapted to flow injection, systematically optimized, and more fully characterized. Its intended application is for measurement of sodium sulfide reagent strength in pulp process streams, and sulfide contamination in effluent from Kraft pulp mills. In the flow-injection method developed, a sample solution containing sulfide is reacted with a mixture of iron(III) and nitrilotriacetic acid under ammoniacal conditions. The absorbance of the intensely-colored green product of this reaction is measured at 636 nm. Excess sulfite is present as a color stabilizer. A linear dynamic range of 20–100 ppm sulfide is readily achieved; the relative standard deviation is less than 1.2% (n = 10) throughout this range, and 0.37% (n = 10) midrange at 60 ppm. The usable dynamic range is 8–250 ppm sulfide. Long-term stability of the method is ensured by periodically performing an automatic cleaning cycle using a hydrochloric acid wash solution. This prevents tube discoloration and removes any precipitates which are formed under strongly alkaline conditions. The sample throuhput rate is at least 30/hr, given alternate acid wash cycles.
Design of a high power, 2.75 GHz relativistic peniotron oscillator
(1992-10) Musyoki, Stephen; Sakamoto, Keishi; Watanabe, Akihiko
In the peniotron oscillator, the kinetic energy of relativistic electrons can be efficiently converted to an electromagnetic wave. This feature makes the peniotron a very attractive source of high power microwaves, which is required in heating of fusion plasma in tokamaks and high gradient particle accelerators. In this report we present the design of a 2.75 GHz relativistic peniotron oscillator which is capable of generating a microwave radiation of 30 megawatt with an efficiency of about 60 %. The experimental test results of the designed cavity are also presented
A static dynamic model for densification of geodetic networks.
(1993) Aduol, Francis O.
in the tradition of several joint papers by the honoree and myself, including E. Grafarend and B. Schaffrin (1974, 1976, 1988) and E. Grafarend, B. Schaffrin, and E. Knickmeyer (1982), I took up the subject again in B. Schaffrin (1984, 1989), N. Tamim and B. Schaffrin (1995) and B. Schaffrin and J. Cothren (1998), now with the emphasis on network densification methods which are rigorous, but which leave tie points unchanged along with their variances and covariances. Such a requirement led to the notion of “reproducing estimators” as first presented by B. Schaffrin (1997). It has been known for a long time that the so-called “dynamic adjustment” of geodetic networks can be interpreted as least-squares collocation, according to H. J. Buiten (1978), which would not yield estimates with the “reproducing property.” Also the “free net adjustment” followed by a Helmert transformation would not per se guarantee identical tie point coordinate estimates unless we “forget” about the deviations whose norm we had minimized, but usually not to zero. So the only “reprodu c - ing” alternative seemed to be given by the formulas of a classical least-squares adjustment with fixed constraint even though the tie points are “ fiducial” in their nature, having typically a full dispersion matrix. Therefore, in the formula for the corresponding variance-covariance matrix we find an add i - tional term which vanishes as soon as the “ fiducial” points become real “fixed” points; see, for i n - stance, B. Schaffrin (1984, 1989). This apparently has been the method, applied by JPL over the years, when they talked about “ fiducial network strategies” as in S. M. Lichten et al. (1989), for instance, without spelling out exactly what they did. In any case, as could have been expected, the latter one was shown not to be the optimal estimator with the “reproducing property” by B. Schaffrin (1997). Instead, the optimum turned out to be the “forgetful dynamic adjustment” where every densification point is found conventionally through least- squares collocation, but the tie points remain unchanged. Consequently, a free adjustment followed by a “forgetful Helmert transformation” must be considered inferior and may no longer be carried out routinely; see also K. R. Koch (1983) and F. W. O. Aduol (1993). Here we try to employ least-squares methodology to generate that “reproducing estimator” which, as we already know, will be optimal in this class
A model for the establishment of an integrated regional geodetic datum
(1993) Aduol, Francis O.
A model for the establishment of an integrated geodetic datum covering a region is treated. The integrated geodetic datum is understood here to comprise the geoid, the reference ellipsoid, and the positional coordinates. A comprehensive unified solution model including the three parameters comprising the datum is considered. The estimation model adopted rigorously incorporates determined prior information in the estimation of the datum parameters. Mathematical models together with the pertinent observation equations are presented, followed by a description of the procedure for the actual setting up of the datum. The observational scheme is based on a system of modular traverses anchored on a trilateration of GPS baselines.
A new method of emittance measurement for electron beams from the Micro-emitter
(1994) Ishizuka, Hiroshi; Nakahara, Yuriko; Kawasaki, Sunao; Musyoki, Stephen; Shimizu, Hiroshi; Watanabe, Akihiko; Shiho, Makoto
Recently a new type of cathode called Micor-emitter has been put in progress. This cathode is a microfabricated field emitter having the characteristics of very low emittance and high brightness. We cannot measure the emittance of the cathode with conventional methods like the pepper-pot method. The reasons are: (1) the angle between the electron orbit and the axis is very small and (2) we cannot focus the electron beam in the vacuum or on the surface of the material since the current density of the cathode is extremely high. For the emittance measurement for such low emittance and high brightness cathode, we need to expand the beam, and measure the beam's cross section without any slits or apertures. We studied and proposed a new emittance measurement method for the Micro-emitter.

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