Design and Fabrication of Double-Layer Crossed Si Microchannel Structure

A four-step etching method is used to prepare the double-layer cross Si microchannel structure. In the first etching step, a <100> V-groove structure is etched on (100) silicon, and the top channel is formed after thermal oxidation with the depth of the channel and the slope of its sidewall being modulated by the etching time. The second etching step is to form a sinking substrate, and then the third step is to etch the bottom channel at 90° (<100> direction) and 45° (<110> direction) with the top channel, respectively. Hence, the bottom channel on the sink substrate is half-buried into the top channel. Undercut characteristic of 25% TMAH is used to perform the fourth step, etching through the overlapping part of the two layers of channels to form a double-layer microchannel structure. Different from the traditional single-layer microchannels, the double-layer crossed microchannels are prepared by the four-step etching method intersect in space but are not connected, which has structural advantages. Finally, when the angle between the top and bottom is 90°, the root cutting time at the intersection is up to 6 h, making the width of the bottom channel 4–5 times that of the top channel. When the angle between the top and bottom is 45°, the root cutting time at the intersection is only 4 h, and due to the corrosion along (111), the corrosion speed of the sidewall is very slow and the consistency of the width of the upper and lower channels is better than 90° after the end. Compared with the same-plane cross channel structure, the semiburied microchannel structure avoids the V-shaped path at the intersection, and the fluid can pass through the bottom channel in a straight line and cross with the top channel without overlapping, which has a structural advantage. If applied to microfluidic technology, high-efficiency delivery of two substances can be carried out independently in the same area; if applied to microchannel heat dissipation technology, the heat conduction area of the fluid can be doubled under the same heat dissipation area, thereby increasing the heat dissipation efficiency.

Promising introduced Black Cottonwood species for bioenergy and forage production

The winter-hardy introduced North American Populus trichocarpa Torr. & Gray is of particular interest. The results of the study of some clones of poplar on the experimental sites of the Voronezh region are presented. It was found that the rootability of standard stem cuttings of poplar was 98-100%. The survival of plants during the first 3-5 years varied from 75 to 100%. The growing season in different years was 135-146 days. The yield of standard cuttings on root-cutting plantations under favorable conditions and optimal age varied in different clones from 592 000 to 1 380 000 pieces per ha. The wood stock at the age of economical exploitability (~25 years) reached 400 m3/ha, while the stock of local balsam poplar at the same age reached 220 m3/ha. The green mass of leaves contained 0.22-0.28 feed units/kg. In addition, the content of digestible protein, calcium, phosphorus, carotene, crude protein, crude fat, crude fiber, nitrogen-free extractives and ash was determined. In general, studied clones of P. trichocarpa can be used in short rotation coppices for bioenergy and feed production, as well as in reclamation plantings. Clones of the poplar can be used in hybridization with black poplars to increase their winter hardiness.

Physiological characters of four lowland chilli varieties (Capsicum annum L.) with root cutting

The root system plays some vital roles in overall plant development, promoting plant anchorage, absorption of nutrients and water, and hormone production. Cutting is an attempt to root regeneration and enhance the plant's metabolism capability, including canopies and roots for high yielding. Non-hybrid chilli can be used as a model plant because Indonesia's chilli yield has not been maximal yet. This research was aimed to determine the physiological characters of four lowland chilli varieties with root cutting. This study was designed using a randomized, complete block design (RCBD) with two factors: root cutting and varieties. The root cutting factor consisted of 4 levels: root cutting in seeding, root cutting in ridging, root cutting in seedling and ridging, and non-cutting. The varieties factor consisted of 4 levels, namely Lembang, Kencana, Tanjung, dan Ungu. The results showed that root cutting in ridging for Kencana, Lembang, and Ungu increased stomatal conductance, transpiration rate, CO2 intercellular, chlorophyll accumulation, photosynthesis rate, and improved fruit yield per plant. However, Tanjung did not respond to root cutting treatment because it did not improve plant physiology characters and fruit yield than non-cutting treatment. It is concluded that root cutting in ridging can be improved plant physiology, which contributes to increasing yield on Kencana, Lembang, and Ungu.

EXPERIMENT AND PARAMETER OPTIMIZATION OF ROOT-CUTTING FOR TRIMMING POSTHARVEST CABBAGE

Trimming for postharvest cabbage is useful to increase its economic value added. For obtaining the optimal root-cutting parameters, a root-cutting test platform based on universal testing machine was designed. Then shear contrast test and orthogonal test were carried out respectively, and shear properties were explained according to root morphology obtained by scanning electron microscope (SEM). The results showed that the effect of sliding-cutting with single-edged cutter was the best. The optimal parameters of cutter thickness, shear position, shear speed and sliding-cutting angle were respectively 0.89 mm, 0.00 mm, 388.94 mm/min and 34.84°, and the shear stress was 28.02 kPa.