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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

A study of the effects of recurrent freezes on winter wheat plants

Pauli, Arland Walter. January 1952 (has links)
Call number: LD2668 .T4 1952 P38 / Master of Science
182

Cold resistance in three varieties of winter wheat as related to nitrogen fractions, total sugar and optical density of diluted cell sap

Zech, Arthur Conrad. January 1959 (has links)
Call number: LD2668 .T4 1959 Z43
183

The dynamic response of cold rooms

Kelles, Gerard Jozef. January 1966 (has links)
Call number: LD2668 .T4 1966 K29 / Master of Science
184

A quantitative measure of the thermal insulation value of certain items of men's wear

Franz, Delores Frances. January 1966 (has links)
Call number: LD2668 .T4 1966 F837 / Master of Science
185

Evaluation of the flexural strength of cold-formed steel studs with embossed flanges

Reynolds, Kevin Brandt January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Cold-formed steel studs, though they are a relatively new building material, have become a mainstay in modern construction. They are favored over traditional lumber studs for their high strength to weight ratio and resistance to insects and rot. Due to their relative newness as a material, new advances in their design and implementation are being developed quite rapidly. One such advancement is flange embossing, a technique used to increase the strength of the connection of screws into the studs. Currently, embossed flanges are not specifically addressed in the North American Specification for the Design of Cold-Formed Steel Structural Members (AISI S100), thereby preventing current design equations from being used to calculate an embossed stud's member properties. An experimental investigation was undertaken to determine what effect, if any, flange embossing has on the nominal flexural strength of cold-formed steel studs as determined using the provisions of AISI S100-07. Studs with embossed flanges were tested in bending and their actual flexural strength was computed. This data was then compared with the nominal flexural strength determined using the AISI Specification, without embossing, to determine if these equations would still be appropriate for the design of embossed studs.
186

To investigate the effectiveness of proprioceptive neuromuscular facilitation combined with heat therapy as opposed to proprioceptive neuromuscular facilitation with cryotherapy in the treatment of mechanical neck pain caused by hypertonic posterior cervical muscles

Francis, Romona January 2005 (has links)
Dissertation submitted to the Faculty of Health in compliance with the requirements for a Master's Degree in Technology: Chiropractic at Durban Institute of Technology, 2005 / Due to sustained partial neck flexion when operating a computer terminal for prolonged periods and by holding a stooped posture being proposed aetiologies for hypertonic posterior cervical muscles and subsequent mechanical neck pain, subjects for this research study were chosen according to their occupation and had to sit at a desk for more the three hours and less than eight hours a day. The purpose of this study was to investigate the effectiveness of proprioceptive neuromuscular facilitation combined with heat therapy as opposed to proprioceptive neuromuscular facilitation combined with cryotherapy in the treatment of mechanical neck pain caused by hypertonic posterior cervical muscles. This was a comparative, randomised, clinical trial consisting of two groups. Group A received proprioceptive neuromuscular facilitation (PNF) combined with heat therapy as their treatment protocol. Group B received proprioceptive neuromuscular facilitation combined with cryotherapy as their treatment protocol. Each group consisted of thirty people between the ages of 25 and 50 who were randomly allocated to their respective groups. It was hypothesized that the analgesic properties related to cryotherapy would result in the treatment group that received PNF stretching combined with cryotherapy yielding better results in terms of objective clinical findings. It was also hypothesized that the therapeutic effects of heat therapy would result in the treatment group receiving PNF stretching combined with heat therapy would yield better results in terms of subjective clinical findings and it is hypothesized that there is an association between the subjective and objective clinical findings between the cryotherapy and the heat therapy groups. The treatment regimen consisted of each participant receiving three treatments over a period of one week and then a one-week follow-up consultation. Subjective data monitored consisted of the Numerical Pain Rating Scale –101 (NRS-101) and the CMCC Neck Disability index. Objective data was collected using the Cervical Range of Motion goniometer (CROM) and the Algometer. At the end of all treatment protocols, statistical (quantitative) analysis was performed to determine whether one treatment protocol was more effective than the other. The analysis of the data collected showed that for all outcomes measured, either of the two treatments was effective overall. Trends suggested optimum treatments were dependent on the age of the patient. Age groups of 46-50 years old, 41-45 years old and the 31-35 years old responded best and improved the most with heat intervention, while age group of 36-40 years old responded best to the cryotherapy intervention. For the youngest age group of 25-30 years old, it did not make a difference whether they received heat therapy or cryotherapy as an intervention. It would seem that the older the patient the more effective the application of heat therapy as a result of the effect of heat therapy on the collagen and elastin fibers within the muscle and its fascia which allowed for increased and sustained improvement of the majority of the age groups represented in this study. Conversely it would seem that the cryotherapy group had only immediate and unsustained effects in the long term, which suggests that the cryotherapy had only a pain relieving function that allowed for the improvement of patients in the study, which when removed resulted in regression to the initial clinical syndrome severity. Most of the outcomes did not show a statistically significant interaction between time, age group and treatment group. The study was underpowered at the age group level, with only 12 subjects per age group. Further studies with a larger sample size in each of the age groups are needed in order to determine whether age is a definitive factor in one treatment being preferred over the other.
187

Thermocouple Measurements without Custom Electronics

Wanis, Paul 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Thermocouple measurements require “cold junction” compensation in order to obtain a correct reading. This compensation has traditionally been done with custom circuitry. In flight test applications where volume and power are at a premium (e.g. weapons flight test) it is desirable to have a more flexible solution that uses standard analog data acquisition channels already available as part of the encoder circuitry and performs compensation with remote software. This can be done via digital compensation, but certain measures must be taken to maintain accuracy and minimize noise. This paper describes some of these techniques and their performance tradeoffs.
188

Strategic culture: the key to understanding German security policy?

Longhurst, Kerry Anne January 2000 (has links)
The thesis sets out to mobilise the concept of strategic culture as a tool to understand German security policy. The main assumptions behind the concept of strategic culture are that security policies emanate from collectively held beliefs and values relating to the use of force and that these values and beliefs emerge over-time and are shaped through formative periods and critical junctures, especially at times of war. Building upon these key assumptions the thesis moves to identify the antecedents of (West) German strategic and then to construct a framework for analysis to apply to aspects of post-Cold War security policy. Three central research questions guide the conduct of the study: What is German strategic culture? Has it changed through the ending of the Cold War? And How does it impact upon behaviour? The thesis holds that Germany has a distinct strategic culture, which emerged in the wake of the Second W orId War and acquired substance and form through the rearming of West Germany in the 1950's. This strategic culture, it is argued, incorporates three types of elements. At its core are beliefs and values relating to the use of force that form its basal fabric, stemming out of this are a range of dispositions or 'security policy standpoints' that actively relate core values to the third element of strategic culture the observable policy manifestations. The thesis identifies (West) German strategic culture through an examination of aspects of the rearming of West Germany which is then presented in the form of a full anatomy of the strategic culture and its constituent parts. Subsequent to this the thesis tackles the issue of change after the Cold War and the relationship between strategic culture and security policy behaviour. These two questions are dealt with through an examination of the transformation of the Bundeswehr since 1990, together with a case study of the· practice of compulsory military service, a policy that has endured since the end of the Cold War. Through its investigation the thesis argues that German strategic culture has persisted after the ending of the Cold War and has come to playa decisive role in shaping security policy behaviour
189

An investigation into the genetic variation of chilling requirement in apple (Malus x domestica Borkh.) progenies

Labuschagne, Iwan Frederick 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Various experiments were undertaken over a period of five years to investigate the feasibility of initiating a large-scale programme of controlled apple breeding and selection for the improvement of climatic adaptation, using budbreak number (NB) as a practical criterion of selection. NB is preferred to time of budbreak as sole criterion on the grounds that early budbreak is associated with low NB under local conditions. Variation within and between adult and juvenile seedling families was investigated and the genetic control of the traits involved was assessed, as well as direct and correlated responses to selection. In initial experiments different rating criteria for NB as measure of chilling requirement were tested in association with vegetative and reproductive budbreak time and flowering duration, viz, a classification index based on number and distribution of budbreak (pDS grade), an index where shoot length with increased budbreak was included in the index calculation (pDS index) and bud break number expressed as number per 100 cm of shoot length (NB index). Variance analysis (ANOVA and Variance component analyses) detected significant variation within seedling families for budbreak time and NB, but estimates of genetic components of variance between families were generally low. High genetic variance among seedlings within families is most likely due to the high level of heterozygosity in the parental cultivars as is characteristic of vegetatively propagated crops. Intra-class correlation coefficients for clones within and between families indicate moderate genetic determination for NB with broad sense heritabilities around 30 percent. Realized heritabilities calculated from response to two-way truncation selection were between 40 and 60 percent. For budbreak time (reproductive and vegetative), the broad sense heritability averaged around 75 and 69 percent, respectively, indicating a high degree of genetic determination. Significant response to selection for NB of one-year-old shoots of young seedlings and from seedlings grown into adult trees showed that pre-selection for increased budbreak successfully identified seedlings genetically inclined to more and better distribution of budbreak within a set time of 21 days after initial budbreak. Correlated responses indicated additional advantages of practical and horticultural value, viz, uniformity and position of bud break, and the number and length of side shoots. In general, it is concluded from responses to two-way selection that utilizable genetic variance in NB is present within seedling families and thus that selection may successfully be applied as an early screening method for increased budbreak in adult trees. The NB index of intact one-year-old shoots under prevailing sub-optimal winter conditions is therefore proposed as criterion of selection for improvement of climatic adaptation, and combined selection utilizing genetic variation between and within crosses as the selection method. / AFRIKAANSE OPSOMMING: Verskeie proewe is oor 'n periode van vyf jaar uitgevoer om die toepaslikheid van 'n grootskaalse appelteel- en seleksieprogram vir die verbetering van klimaatsaanpasbaarheid te ondersoek met 'aantal knopbreke' (NB) as praktiese seleksiekriterium. NB word verkies bo tyd van knopbreek op grond daarvan dat vroeë knopbreek onder plaaslike toestande met lae NB gepaard gaan. Variasie binne en tussen volwasse en jong saailingfamilies en die genetiese beheer van die betrokke eienskappe is ondersoek, asook direkte en gekoreleerde seleksieresponsie. In die aanvangs-eksperimente is verskillende kriteria vir die kwantifisering van aantal knopbreke getoets as potensiële maatstawwe van die inherente kouebehoefte in appelsaailinge. Die tyd van vegetatiewe en reproduktiewe knopbreek en blomperiode is ook getoets. Die volgende indekse is gebruik: 'n klassifikasie-indeks om die aantal en verspreiding van knopbreke te beskryf (pDS graad), 'n indeks waar die lootlengte, met verhoogde aantal knopbreke, ingesluit is in die berekening van die indekswaarde (PDS indeks), en knopbreke uitgedruk as die aantal per 100 cm lootlengte (NB indeks). Variansie analise (ANOVA en variansie komponent analise) het betekenisvolle variasie binne saailingfamilies aangetoon vir tyd van, en aantal knopbreke. Ramings van genetiese komponente van variansie tussen families was relatief klein. Hoë genetiese variansie tussen saailinge binne families is waarskynlik te wyte aan die hoë vlak van heterosigositeit in die ouergenotipes, wat kenmerkend is van gewasse wat vegetatief voortgeplant word. Intraklas korrelasie koëffisiënte vir klone tussen en binne families het gedui op 'n middelmatige oorerflikheid in die breë sin (ongeveer 30 persent) vir aantal knopbreke. Verhaalde oorerflikhede wat bereken is vanaf responsie op twee-rigting atknottingsseleksie was tussen 40 en 60 persent. Vir tyd van knopbreek (vegetatief en reproduktief) was die breësin oorerflikhede ongeveer 75 en 69 persent, onderskeidelik, wat aanduidend is van 'n hoë graad van genetiese bepaling. Betekenisvolle responsie op seleksie vir NB van jong saailinge en saailingbome wat volwassenheid bereik het toon dat pre-seleksie vir knopbreke saailinge kan identifiseer wat geneties meer knopbreke en 'n beter verspreiding van knoppe binne 'n periode van 21 dae na die eerste knopbreek lewer. Gekorreleerde responsie op seleksie toon 'n addisionele voordeel van praktiese en tuinboukundige belang, naamlik, meer en langer sylote. In opsomming kan dit gestel word dat responsie op twee-rigting seleksie bruikbare genetiese variasie vir NB binne saailingfamilies ontgin het en dat seleksie vir verhoogde aantal knopbreke suksesvol toegepas kan word. Die NB indeks op een-jaar-oue hout word dus voorgestel as seleksiekriterium vir verbetering van klimaatsaanpasbaarheid onder plaaslike sub-optimale wintertoestande, en gekombineerde seleksie "combined selection" wat genetiese variasie binne en tussen kruisings benut as seleksiemetode.
190

Facilities design in the cold storage industry

Tang, Wing-piu, Richard, 鄧永彪 January 1978 (has links)
published_or_final_version / Industrial Engineering / Master / Master of Science in Engineering

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