The paper contains short description of a special device developed for study of electrical after-effect in vegetable cellular tissues after short electric pulses applied to the tissue. The device contains generator of the pulses and the microprocessor controlling circuits for time arrangement of the pulse amplification and collection of data for further evaluation. The pulses are based on AC signal with frequency 10-100 kHz with the amplified voltage up to ±240V and duration 1-10 ms. After finishing the individual pulse, the AC source signal continues, but amplitude on the tissue is 21. 5times lower. The data about AC voltage and current intensity are continuously collected with frequency 800 kHz and then fed to PC USB input that was used to calculate time chart of electric properties of the tissue, its complex permittivity and specific complex conductivity. An example of the obtained results on potato tissue is given. and Práce obsahuje krátký popis speciálního zařízení vyvinutého pro studium elektrických jevů v zeleninové buněčné tkáni po krátkých elektrických pulsech. Zařízení se skládá z generátoru nosného signálu, mikroprocesorem řízené jednotky pro amplitudovou modulaci uvedeného nosného signálu, zesilovače pro výkonové zesílení a jednotky pro sběr dat pro další vyhodnocení. Užívá se nosný signál frekvence 10-100 kHz, modulovaný do pulsů strváním 1-10 ms a amplitudě do ±240 V. Po skončení individuálního pulsu střídavý signál pokračuje, ale jeho amplituda se snižuje 21,5krát; měření na tkáni pokračuje jako nedestruktivní. Data okamžitých hodnot napětí a proudu na zkoumané tkáni jsou snímána sfrekvencí 800 kHz. Tato data jsou přivedena na USB vstup PC a zde použita k výpočtu časového průběhu elektrických vlastností tkáně, její komplexní permitivity a měrné komplexní vodivosti. Analýza je demonstrována na příkladu (pletivo bramboru).
Seedlings planted on degraded lands experience high leaf temperature in daytime because of the lack of vegetation shading. The effect of high temperature on the photosynthetic capacity was investigated in Dipterocarpus obtusifolius Teijsm. ex Miq. and D. chartaceus Sym. seedlings planted on degraded sandy soils in southern Thailand. Neither species showed decrease in photosynthetic capacity at leaf temperature over 38 °C as compared to that at 28 °C. D. obtusifolius showed higher photosynthetic capacity at high temperatures. Enhanced photosynthetic capacity at high temperatures would be a key for high photosynthetic performance of D. obtusifolius planted on degraded sandy soils. and M. Norisada, K. Kojima.
Anticoccidial efficacy of a drug combination containing monensin at 8 p.p.m. plus the new antioxidant duokvin at 120 p.p.m. in the feed was compared with that of monensin alone at the recommended level of 100 p.p.m. against a field isolate of the coccidium Eimeria acervulina Tyzzer, 1929 in a battery study. Both monensin and monensin duokvin combination were effective against E. acervulina when judged by weight gain, feed conversion and faecal scores. There was no significant difference in the chemoprophylactic activity of either treatments. Neither monensin at 100 p.p.m. nor the combination proved effective in terms of oocyst production. In accordance with the earlier findings with E. lenella, the combination seems appropriate for field trials.