4 research outputs found
Perflorooktanoik asit ile uyar lm testiküler hasarlara kar Giresun f nd k ya n n koruyucu etkileri
No full textBu çal mada yayg n çevresel kirletici olan perflorooktanoik asit (PFOA) ile uyar lm testiküler hasarlara kar Giresun f nd k ya n n koruyucu etkisi ara t r lm t r. Balb/c yeti kin erkek farelerin kullan ld deneysel a amalarda; kontrol grubu, PFOA uygulanan grup, Giresun f nd k ya uygulanan grup ve PFOA+Giresun f nd k ya uygulanan grup kullan lm t r. Bu gruplara ait vücut ve testis a rl , sperm say s , sperm canl l , sperm morfolojisi, sperm motilitesi, serum testosterone seviyesi de i imleri izlenmi ve farkl l klar istatistiksel olarak s nanm t r. Ayr ca, genel histolojik de erlendirme ve TUNEL immunohistokimyasal de erlendirme yap lm t r. Sonuç olarak, vücut a rl , testis a rl , sperm say s , sperm motilitesi, sperm canl l ve serum tetosteron seviyesindeki azalmalar n yan s ra histolojik deformasyonlar PFOA uygulamalar n n hedef dokuya yönelik seçici bir etki gösterdi ini ortaya koymu tur. Bununla birlikte, Giresun f nd k ya uygulamalar n takiben histolojik ve biyokimyasal parametrelerdeki belirgin iyile meler, PFOA kaynakl toksik etkilerin önemli ölçüde bask land n göstermi tir
THE PROTECTIVE EFFECT OF CLOSE FOLLOW-UP DURING THE PANDEMIC ON ADOLESCENTS WITH AN EATING DISORDER
No full textUtilisation of Single Tooth Procedures to Establish the Cutting Mechanics of Woodworking Hand-saw Teeth
No full textThe work reported in this thesis details the original research undertaken by the author into the cutting mechanics of wood-working handsaw tooth geometries. The research can be separated into three distinctive sections. The first section is a review of both fundamental and recent literature regarding wood characteristics and machining processes. The second section documents the findings of a cutting process in which a variety of work-piece parameters were evaluated whilst limiting the parameters associated with tooth geometry. The third and final section documents the findings of a cutting process in which a variety of tooth geometry parameters were evaluated whilst limiting work-piece variation.
Two separate experimental procedures were developed to carry out the work for sections two and three respectively: The first of these procedures utilised a CNC router machine to perform the controlled cutting action. A single “rip” tooth was attached to the tool holder. The workpiece was constrained to a tri-axis dynamometer which was used to measure the resultant tool forces in the relative X, Y and Z axes. At the same time a universal testing machine was employed to perform mechanical test procedures on a variety of wood species. A predictive cutting force model was developed using the obtained mechanical properties as categorical predictors.
The second procedure utilised a shaper machine to perform the controlled cutting action. Three different saw tooth geometries were evaluated for only one variety of wood species. A tri-axis dynamometer was again used to measure the resultant tool forces. The geometric parameters of each tooth were carefully evaluated at using SEM micrographs. A predictive cutting force model using the geometric parameters as categorical predictors was developed.
Chip and surface formation was carefully evaluated. For procedure one this involved observation of the chip/surfaces under an optical microscope. For procedure two this involved capturing footage of the cutting process using a high speed camera.
The findings of the research show that un-bevelled teeth with orthogonal edges generally yield high cutting forces. However, these teeth are very effective at removing material along the wood grain in a “chisel like” cutting action. Bevelled teeth with sharp lateral edges generally yield low cutting forces. These teeth are well suited to severing the wood fibres perpendicular to the grain in a “knife like” cutting action
The social and ritual contextualisation of Ancient Egyptian hair and hairstyles from the Protodynastic to the end of the Old Kingdom
No full textHair, the most malleable part of the human body, lends itself to the most varied forms of
impermanent modifications. The resulting hairstyles convey social practices and norms,
and may be regarded as part of the “representation of self” and an integral element in
the maintenance and structuring of society. In this thesis, a systematic and quantative
investigation has been undertaken of the structural relationships between variations in
hairstyles and principal changes in social organisation in ancient Egypt from the
Protodynastic to the end of the Old Kingdom (3,350-2,181 BC), a period that witnessed
the rise, consolidation and eventually breakdown of centralised authority.
The results reveal that hairstyles were linked to the identity of individuals and
social groups, such as men, women, children and the elderly. Hairstyles were used as a
means of displaying status. After experimentation with a broad spectrum of hairstyles
during the Protodynastic and early Dynasty I, an institutionalised canon for hairstyles
was established, coinciding with the creation of administrative institutions. These
codified hairstyles continued to serve as the norms for identifying members of the
administration or signs of authority. By the end of the Old Kingdom, the hairstyles of
the elite had been adopted by the lower officials of the increased bureaucracy and
provincial elites as representations of their newly acquired power and status.
Although initially the majority of the men had their hair cut short, modifications
of short hair and the adoption of mid- and shoulder-length hair became progressively
common. The use of certain hairstyles was restricted to the higher social offices, with
longer hair being emblematic of power and divinity. Women, by contrast, initially had
long hair with greater variety occurring by Dynasty I and a more restricted array from
Dynasty II onwards. However, long hair was predominant among women of all social
statuses in all periods. Long hair may have thus been related to the perception of women
as mothers (responsible for childbirth and nursing), and hence their perceived role as
directly linked with procreation and fecundity. Although the adoption of the tripartite by
high officials was related to this ‘generative’ aspect of feminine hairstyles, it was
primarily in imitation of the God Osiris and his regenerative powers
