Robust penetrating microelectrodes for neural interfaces realized by titanium micromachining

Neural prosthetic interfaces based upon penetrating microelectrode devices have broadened our understanding of the brain and have shown promise for restoring neurological functions lost to disease, stroke, or injury. However, the eventual viability of such devices for use in the treatment of neurological dysfunction may be ultimately constrained by the intrinsic brittleness of silicon, the material most commonly used for manufacture of penetrating microelectrodes. This brittleness creates predisposition for catastrophic fracture, which may adversely affect the reliability and safety of such devices, due to potential for fragmentation within the brain. Herein, we report the development of titanium-based penetrating microelectrodes that seek to address this potential future limitation. Titanium provides advantage relative to silicon due to its superior fracture toughness, which affords potential for creation of robust devices that are resistant to catastrophic failure. Realization of these devices is enabled by recently developed techniques which provide opportunity for fabrication of high-aspect-ratio micromechanical structures in bulk titanium substrates. Details are presented regarding the design, fabrication, mechanical testing, in vitro functional characterization, and preliminary in vivo testing of devices intended for acute recording in rat auditory cortex and thalamus, both independently and simultaneously

Studies on noise pollution in cotton ginneries

Cotton ginning systems contain numerous types of machinery-each of which is a source of noise and contribute to the overall noise level. Noise pollution in cotton ginneries has never received attention in the past in India. Noise levels of different machineries used in cotton· ginning systems were studied. The likely effect of noise on workers\u27 health and the possible ways of reducing the noise levels were suggested. Noise levels for roller gins were found to vary from 87.0 to 97.7 dBA under no load and from 85.9 to 97.7 dBA under load condition. Noise for double roller gins were found above permissible exposure limit of 85 dBA. Gearbox of the double roller gin was found to generate more noise than other moying elements of the gin. Noise levels of pre-cleaners and lint cleaners were found below the permissible limit. In press house noise level was observed in the range of 793 to 93.5 dBA for different models of presses. Gin house was found to be the noisiest workstation with an average noise level of 96.0 dBA. The noise level for the workstations such as raw cotton suction fan, pre-cleaner, gin house central platform, seed blower and press operator room were observed above the permissible exposure limit Exposure to such a noise may adversely affect overall efficiency, safety, and hearing ability of workers. Protecting them from loud noise by employing technical and personal measures of noise control can create· healthful working conditions in ginneries

Cellulase Dissolution: Electron Microscopic Technique for the Study of Chemically Modified Cotton

17-24<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Cross-sections of some ethers and esters of cotton cellulose at different degrees of substitution were examined electron microscopically by the cellulase dissolution technique. The results have confirmed that this technique has many advantages over the conventional cuene dissolution technique and can be used effectively as a microsolubility test for examining a wide range of chemically modified cottons. The cellulase of Penicillium funiculosum acts exclusively on the unreacted cellulose of the modified cotton and unlike cuene does not distort the ultra structural morphology of the cross-section. This technique also enables quick evaluation of cotton modified for mildew and rot resistance.</span

Optimizing the frequency of oscillating beater in double roller gin

184-188Variable speed double roller gin has been used to optimize the frequency of oscillating beater, considering three levels of oscillating frequency, namely 750, 1000 and 1250 cpm and conventional frequency of 1000 cpm. The factors considered for optimum rates include lint turn out, fibre quality and ginning rate. Overall, the fibre quality remains unaffected for all types of cottons, whereas the lint out-turn and ginning rate are found to be highest at 1250cpm frequency for long and extra long staple cottons. The conventional frequency is found to be better for short staple cottons. The short fibre content, seed coat neps and neps in the lint are comparatively less at higher frequency

Variation in the size of fibre base in diploid and tetraploid cotton varieties in relation to the strength of attachment and seed coat removal

67-72<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The morphology of the fibre base of cotton lint from three regions of the seed, viz. micropylar, side and chalazal, of both diploid and tetraploid cotton cultivars has been studied by scanning electron microscopy. In general, the size of the fibre base is maximum at the micropylar region followed by side and chalazal regions. The energy required to pull the fibres from the micropylar region is also maximum in both diploid and tetraploid cottons. However, the incidence of seed coat fragments, which is mostly due to the removal of chalazal cap during ginning, could not be correlated with the size of the fibre base from this region.</span

Electron Microscopic Studies on Cotton Knits Durable Press Finished by Different Techniques

45-52<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Two cotton knitted fabrics, one of honeycomb and the other of sinker body structure, were durable press finished with dimethylol dihydroxyethylene urea (DMDHEU) using three techniques, viz. pad-cure, moist-cure and wet-fix treatment with and without the polymeric stiffening additive Daikanol AMH in the treatment bath. Scanning and transmission electron micrographs of the finished knitted fabrics showed that the finishing conditions employed in each technique have a profound influence on the extent of swelling and uniform distribution of DMDHEU crosslinks in the finished fabrics. The moist-cure finished samples showed more uniform swelling and distribution of crosslinks as compared to the pad-cure and wet-fix treated samples. The use of the polymeric stiffening additive Daikanol AMH in the wet-fix treatment bath gave a mixed cross-section of both the collapsed and swollen structures with predominance of the latter.</span