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Adsorption of volatile n-Alkanes and polar organic solvents by water hyacinth (Eichhornia crassipes) root biomass: Thermodynamics, mechanism and effect of chemical treatment
No full textThe use of lignocellulosic materials as biosorbents has both environmental and
economic benefits. They are biodegradable, safe to use and most importantly renewable
and less costly. The objectives of this present study were to study the effect of treatment
on the performance of water hyacinth root biomass as a biosobent for n-hydrocarbons
and polar organic solvents. Water hyacinth, a lignocellulosic material was chemically
treated by two methods, nitric acid and organic solvent. The effect of the treatment was
studied by Fourier Transform Infra-red (FT-IR) spectroscopy, Thermogravimetric
analysis, X-ray diffraction (XRD), scanning electron microscopy and other analyses.
FT-IR absorption bands were obtained at 3421, 2855, 1457 and 1035 cm-1 (O-H stretch,
C-H vibration, C-H asymmetric deformation, and C-O stretch, respectively) and 1508,
1541 and 1559 cm-1 (all aromatic skeletal vibrations characteristic of lignin), as well as
a C=O carboxylate stretch vibrational band at 1654 cm-1. The chemical composition
and FT-IR analyses showed that treatment resulted in a decrease in the amount of lignin
in the biomass. X-ray diffraction and scanning electron microscopy confirm the root
biomass to be amorphous and not to have a strongly structured surface. The XRD
revealed that treatment increased crystallinity. Thermogravimetric analysis studies
displayed that the treated biomass is more thermally stable than the untreated biomass.
The surface area of the biomass increased upon treatment. Thermodynamic parameters
for the adsorption of n-alkanes hexane to nonane on ground dried water hyacinth
(Eichhornia crassipes) root biomass were studied between 40oC and 70oC column
temperature using gas solid chromatography, before and after treatment of the root
biomass with mineral acid and organic solvent. The enthalpy of adsorption (ï„Ha) values
of 20.42KJ.mol-1 for hexane to -44.44KJ.mol-1 for nonane were obtained for the
adsorption of the n-alkane series on untreated water hyacinth root biomass. Mineral
acid and organic solvent treatments led to greater adsorption bond strength, with ï„Ha
values of -34.01 to -36.33 kJK-1mol-1 respectively after mineral acid treatment, and -
40.98 to -46.7 kJ.mol-1 after organic solvent treatment. Factors affecting the adsorbentadsorbate
interaction are discussed. The adsorption properties of dried water hyacinth
root biomass towards four polar solvents (dichloromethane, ethylacetate, diethylether,
and acetone) were studied by inverse gas chromatography between 400C and 700C. The
enthalpy of adsorption (ï„Hads) values obtained for the polar probes range from -51.234
for acetone, an amphoteric probe to -74.658 kJ.mol-1 for dichloromethane an acidic
probe for untreated biomass. Mineral and solvent treatments led to reduction in the
values of enthalpy of adsorption due to removal of high energy sites on the surface of
water hyacinth root biomass. The Lewis acidity, Ka, and Lewis basity Kb parameters
were calculated from the net retention volumes, Vn of the probes. The b a K K ratios
for the untreated, acid-treated and organic solvent treated biomass were found to be
9.2175, 6.7425 and 6.5733 respectively, indicating that all the surfaces of the untreated,
mineral acid and organic solvent treated water hyacinth root biomass are basic in nature
Influence of Culture on Succession Planning in Small Family Owned Businesses in Bulawayo Central Business District.
No full textFamily businesses are becoming the dominant entrepreneurial force in today’s global economy but their poor survival rate is a continuing cause of fretfulness around the world. Family businesses provide jobs to a large unskilled population and contribute to the stability and growth of Zimbabwe’s economy. However family firms experience disquieting failure rate in their second generation of operation and an exacerbated failure rate in their third generation.
Family businesses are founded and managed by families as such they are family specific. This characteristic determines the extent to which “family specific culture†influences the succession planning of these firms. The firm’s culture has a relatively weak influence on an individual’s core culture beliefs and values. This study therefore examined the influence of cultural values such as inheritance laws, primogeniture, gender egalitarianism and succession phobia on small family businesses located in the CBD of Bulawayo.
The study used informal interviews, structured interviews and a questionnaires to obtain data from a sample of 38 small FOBs in various sectors. The data gathered was analyzed using qualitative research approach to determine the relationship between the study variables. The findings of the study points out that cultural determinants in the study have a significant influence on the successful orchestrating of succession of family businesses. The inheritance laws has the highest magnitude effect on succession of family business
A conceptual model depicting the influence of culture on succession process was developed. A new paradigm shift is necessary to put in place sound policies in business operations and succession plans to forestall any problems that may perhaps arise through cultural philosophies. Thus through this approach longevity of these businesses can be achieved. Understanding cultural factors that influence succession in family firms is the keystone to reducing the high mortality rate of this important segment in the economy.,Lupane State Universit
An evaluation of the effectiveness of Retention strategies in Zimbabwean Parastatals. A case study of Zimbabwe National Water Authority
No full textThe main thrust of this study carried out is to evaluate the effectiveness of retention strategies in Zimbabwean parastatals. Human capital is a precious commodity that plays a pivotal role within the organisation and contributes directly to its success or failure. Central to this philosophy, organisations should craft strategies to retain their critical talent in this cut throat war for talent. The research was inspired by the notion that if employees are satisfied and motivated by the working environment, compensation, career growth, employee relationship and organizational support they are likely to stick around the organisation for a lengthy period of time. This study was conducted at ZINWA which means the research design was a case study. The researcher used convenience and judgmental sampling methods. The information was obtained through conducting interviews and administering questionnaires to 35 respondents and 29 of them responded. The study was approached using the mixed methodology, quantitative data was analysed statistically and thematically for qualitative data. Study results revealed that parastatals have some effective retention strategies in place mostly for the top management which brought dissatisfaction to the lower level employees. Most of the lower levels employees acknowledged that there are other reasons for staying with the organization not because the strategies are effective. In view of this, the researcher recommended that these strategies should cascades to the lower levels. Future researchers in this subject are challenged to further look into this issue particularly on a broader perspective as this research only looked at one organization,Lupane State Universit
To Investigate the Impact of RBM as A Performance Management Tool On Teachers Performance: A Case of Insiza District, Matabeleland South Province
No full textPerformance management is a very critical process in an organisation. It greatly influences the levels of productivity, service delivery and the image of the organisation. The quest for better outcomes/results has resulted in several performance tools being implemented such as Results Based Management (RBM). Employees should effectively and efficiently discharge their duties to enable the organisation to meet its goals and objectives. The objective of this study was to investigate the impact of RBM as a performance management tool on teachers’ performance: A case of Insiza District Matabeleland South Province. Previous research has proved that RBM helped many organization sand countries to achieve better results. This is because RBM is built upon the tenants of continuous improvement. A sample size of seventy (70) employees was drawn from a population 700 teachers. Systematic random sampling was used and data was collected through questionnaires and interviews. The results of the study were analyzed through tables, graphs and pie charts. Results showed that RBM is being used as a performance management tool but its impact is to a lesser extent as showed by the pass rate on examination classes. When RBM was introduced the idea was to provide a long lasting solution to the problems being faced,Lupane State Universit
An Assessment of the effectiveness of entrepreneurship training in high schools. A case study of lead us today trust programmes in Bulawayo.
No full textThis study intends to analyze the effectiveness of the entrepreneurship training to High school students using Lead Us Today Trust programs in Bulawayo as a case study. The researcher used qualitative method in gathering the necessary data, with questionnaires and interviews being the data collecting tools. Purposive sampling was used with 25 respondents from O’level and A’level between the ages of 13 to 17. The analysis suggests that the Lead Us Today programs are very much effective in the equipping the students with entrepreneurial skills. In conclusion, the study revealed that the training programs are a relevant factor for young people as it brings youth and community development
An Investigation into the Effectiveness of Community Service Sentencing Option as a Rehabilitation Tool: a case of Bulawayo
No full textZimbabwe introduced penal reforms in its criminal justice system in 1994. These reforms were prompted by pressure over continuous use of prisonisation as the preferred means of punishing wrongdoers. That is how Community Service Orders, a non-custodial measure, as an alternative to imprisonment came into being. Community service is embedded in the reformative theory of punishment and was seen as a sustainable approach to develop reintegration of offenders into their communities, reassure reconciliation, as well as reduce recidivism, the challenges of overcrowding and the high costs to taxpayers and government in maintaining prisoners. This study was based on the overall objective, which was to investigate the perceived effectiveness of the community service programme as a rehabilitation tool in Bulawayo. Offenders, victims and their families as well as members of the judiciary were interviewed, in addition, possible recommendations for the effective implementation of community service are given that can contribute to its success and sustainability if put into operation by the relevant stakeholders. The study was qualitative in nature and relevant information was gathered through, in-depth interviews, focus group discussions and questionnaires and literature review was conducted to come up with the theoretical framework and background to the study. Data was analyzed using content analysis method. The study findings were that the community service programme has been accepted by the community for encouraging reconciliation and the reintegration process of the offenders into their societies. This is despite the perception by some members of the community that the sentence is a soft option. The study findings also revealed challenges which are: an existing discord between stakeholders which require urgent attention to address cases of recidivism, inadequate funding and a management structure headed by a principal community service and a dysfunctional district committee
Communal farmers’ perceptions of tick-borne diseases affecting cattle and investigation of tick control methods practiced in Zimbabwe
No full textTick borne diseases (TBDs) are responsible for huge economic losses in cattle production in most African countries where the majority of cattle owners are the resource poor communal farmers. Governments have initiated and co-ordinate tick control programs with farmers required to contribute funds for their sustenance. The success of these programs will hinge upon the involvement of communal farmers in their design, implementation and evaluation. To this end, 313 communal farmers (approximately 8.4% response rate) were interviewed and 3 focus group discussions were carried out in the southern low-veld part of Zimbabwe with the objectives of investigating communal farmers' perceptions on TBDs affecting cattle, level of participation in government initiated tick control programs, other tick control methods practiced, types of acaricides used and their perceived effectiveness. There was a general awareness of TBDs with 67.7% (n=212) farmers being able to describe tick diseases with names or clinical and post-mortem signs. The diseases or problems frequently associated with ticks were cowdriosis (38%, n=119), mastitis (36.7%, n=115), anaplasmosis (36.1%, n=113), body damage (28.4%, n=89), babesiosis (24.6%, n=77) and poor body condition (16.6%, n=52). Cattle mortalities due to TBDs were reported by 23.8% (n=74) of the farmers. The plunge dip was consistently used by farmers (70.3%, n=220) to control ticks. Other tick control methods practiced were the hand spraying (67.4%, n=211), hand dressing (16.6%, n=52), traditional methods (5.4%, n=17), use of pour-ons (4.5%, n=14) and smearing (2.2%, n=7). The formamidines were the most common class of acaricide used (59.4%, n=186), followed by synthetic pyrethroids (29.1%, n=91), macro cyclic lactones (12.8%, n=40) and organophosphates (4.5%, n=14). Most farmers (75.2%, n=231) perceived these acaricides to be effective in controlling ticks. The results of focus group discussions showed that a number of factors influenced the success of government initiated tick control programs and these included inconsistent supply of acaricides, unaffordable dipping fees, lack of water, long distance to the dip tank, lack of information on dipping procedures and lack of knowledge on strategies for delaying acaricide resistance. This study demonstrates that while farmers can be a valuable source of information with regards to the epidemiology of tick borne diseases affecting their cattle, there is still need for further training in understanding the TBDs and strategies for their control
A Note on the Discrete Spectrum of Gaussian Wells (I): The Ground State Energy in One Dimension
No full textThe ground state energy ð¸ 0(ðœ†) of ð» 𜆠= − ð‘‘ 2 /ð‘‘ð‘¥ 2 − 𜆠𑒠−ð‘¥2 is computed for small values of 𜆠by means of an approximation of an integral operator in momentum space. Such an approximation leads to a transcendental equation for which 𜖠0 ( 𜆠) = | ð¸ 0 (ðœ†)| 1/2 is
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Exploring the role of feminine indigenous knowledge on seed selection, post-harvest handling and its contribution to household food security: a case of Skuta Ward 19 in Insiza District
No full textFood security has become a more pronounced global problem in recent years with the threat posed by recent trends such as climate change, rainfall scarcity and recurrent droughts. This together with the size of the world’s growing population gives urgency for the revival and integration of indigenous knowledge systems in farming, particularly women’s local wisdom in seed selection, food processing and post-harvest handling among local communities of Skuta, ward 19. Women were identified as custodians of traditional scientific knowledge on seed selection, preservation and storage. Ash mixtures and smoke coating were the dominant preservatives used to preserve most seeds and grain crops for long term use. These traditional methods ensured that people had at least sufficient food, if not surplus until the next harvesting period. Gender roles were determined by location of activity, time needed, physical labor demanded, stereotypes and technology used. Agricultural modernization had negatively impact not only on the production of indigenous crops but also on the use of traditional methods of processing and preservation of grain crops. This study recommends a marriage of convenience between the two knowledge systems through both formal and informal institutions in ensuring sustained food security. Women must be included in agricultural research and food security interventions as resources of IK
