Mesoporous Silica Preparation Using Sodium Bicarbonate as Template and Application of the Silica for Hydrocracking of Used Cooking Oil into Biofuel

Silicon - The hydrocracking of used cooking oil into biofuel over mesoporous silica was systematically studied. This research aims to induce the silica pores using NaHCO3 and employ the heteropore...     

Massive MIMO pilot assignment optimization based on total capacity

We investigate the effects of pilot assignment in multi-cell massive multiple-input multiple-output systems. When deploying a large number of antennas at base station (BS), and linear detection/precoding algorithms, the system performance in both uplink (UL) and downlink (DL) is mainly limited by pilot contamination. This interference is proper of each pilot, and thus system performance can be improved by suitably assigning the pilot sequences to the users within the cell, according to the desired metric. We show in this paper that UL and DL performances constitute conflicting metrics, in such a way that one cannot achieve the best performance in UL and DL with a single pilot assignment configuration. Thus, we propose an alternative metric, namely total capacity, aiming to simultaneously achieve a suitable performance in both links. Since the PA problem is combinatorial, and the search space grows with the number of pilots in a factorial fashion, we also propose a low complexity suboptimal algorithm that achieves promising capacity performance avoiding the exhaustive search. Besides, the combination of our proposed PA schemes with an efficient power control algorithm unveils the great potential of the proposed techniques in providing improved performance for a higher number of users. Our numerical results demonstrate that with 64 BS antennas serving 10 users, our proposed method can assure a 95%-likely rate of 4.2 Mbps for both DL and UL, and a symmetric 95%-likely rate of 1.4 Mbps when serving 32 users.     

Health promoting properties of protein hydrolysates produced from oil palm (Elaeis guineensis) kernel

This study aimed to determine the lipid-lowering properties, antioxidant capacity (AC) and angiotensin-I converting enzyme (ACE)-inhibitory activity of oil palm kernel protein hydrolysates (OPKHs) that were produced using protease and pepsin-pancreatin hydrolysis. The effects of the OPKHs on apolipoprotein B (apoB) secretion was assessed using HepG2 cells as a model and the AC of the OPKHs was determined based on ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP). Both protease and pepsin-pancreatin hydrolysates reduced apoB secretion significantly (p<0.05). The OPKHs scavenged ABTS radicals effectively and demonstrated a high reducing power even at a low concentration (1 mg/mL). The AC of the OPKHs was significantly correlated with the OPKHs protein content. However, the OPKHs demonstrated very low ACE-inhibitory activity. The pepsinpancreatin hydrolysate demonstrated significant lipidlowering properties, favourable AC and ACE inhibitory activity in compared to protease hydrolysate. Therefore, OPKH demonstrate the potential as a nutraceutical for functional foods.     

Effects of Modified Atmosphere Packaging on the Physicochemical Characteristics of Ciku ( Achras sapotaL) at Various Storage Temperatures

The physicochemical changes in ciku during storage at various temperatures and the effect of various techniques of modified atmosphere packaging (MAP) at 5, 10, 15°C and ambient were examined by monitoring fruit texture, weight loss, soluble solids content, pH, sucrose, fructose, glucose, pectin, tannin, ascorbic acid and microbial infection. Under MAP, ciku could be stored for 4 weeks at 10°C and 3 weeks at 15°C, while without MAP the storage life was shorter by 1 week. Packaging in low-density polyethylene film (LDPE) was highly effective in maintaining the texture and weight of cold-stored fruits. Fruits stored at 5°C experienced chilling injury, observed as their inability to ripen properly, even after 3 days at room temperature in the presence of 50 g kg⁻¹ calcium carbide. The ascorbic acid content was highest in vacuum-packed fruits followed by the other LDPE packagings. LDPE packaged fruits also received the highest sensory scores for taste, colour, texture and overall acceptability in cold-stored ciku. The unsealed nature and heating involved in shrink wrapping did not favourably affect the storage life of ciku. MAP alleviated the chilling injury which occurred in ciku stored at 10°C but not at 5°C.