The aim of the present research is first to reduce the jute fabric non-cellulosic components by using different chemical modifications (i.e. alkali and oxidative) and then to analyze their influence ...on the jute fabric properties. For that purpose, the jute fabrics were characterized in terms of their chemical composition, structural parameters, mechanical properties, volume electrical resistivity, antibacterial activity and biosorption of Zn
2+
. Moreover, the jute fabrics were functionalized by incorporation of silver ions and the fabrics were evaluated as sorption material with a further perspective of reuse. After the alkali modifications, the hemicelluloses were selectively removed and the fabric structural parameters increased. Alkali modifications under mild conditions (1% NaOH for 30 min and 5% NaOH for 5 min) lead to a decrease, while the most intensive alkali modification (17.5% NaOH for 30 min) contributed to an increase in the volume electrical resistivity and fabric maximum force compared to unmodified fabric. A relationship between the jute fabric chemical composition, crystallinity index, conversion of cellulose I to cellulose II, fabric structural parameters and volume electrical resistivity was found. The oxidations lead to selective lignin removal, which consequently causes a decrease in the volume electrical resistivity and fabric maximum force. Ag
+
incorporated in the selected samples decreased their electrical resistivity even further. Following the increased focus on the concept of circular economy and sustainable development goals, the biosorption potential of damaged and waste jute fabrics for Zn
2+
was investigated. Jute fabrics with incorporated Ag
+
and those obtained after the biosorption of Zn
2+
provided maximum bacterial reduction (99.99%) for
Escherichia coli
and
Staphylococcus aureus
. The chemically modified jute fabrics can be utilized as carpet backing and protective clothing in environments sensitive to electrical discharges, but also as filters for water disinfection and biosorbents for Zn
2+
.
Graphic abstract
The influence of the chemical composition on the biosorption potential of waste jute fabric for Ni
2+
, Cu
2+
, and Zn
2+
was investigated. The raw jute fabric was treated with sodium hydroxide or ...sodium chlorite to selectively remove hemicelluloses and lignin, respectively. All jute fabrics were characterized by determination of their chemical composition as well as functional group content. The effects of solution pH, contact time, and initial metal ion concentration on the biosorption from monometallic and polymetallic solution by jute fabrics were investigated. The maximum biosorption capacity for all heavy metal ions was observed at pH 5.5. Concerning the contact time, the raw jute fabric shows more than 72 % of the total uptake capacity of Ni
2+
, Cu
2+
, and Zn
2+
within 1 h, while the jute fabrics with lower hemicelluloses and lignin content show between 72–85 % of the total uptake capacity within 3 h. Increased initial metal ion concentration from 10 to 20 mg
/l
in monometallic solution caused an increase in the total uptake capacity of jute fabrics with lower hemicelluloses and lignin content for 47–69 % (Ni
2+
), 42–63 % (Cu
2+
), and 22–37 % (Zn
2+
). The biosorption capacity of alkali treated jute fabrics was affected by the changes in the total amount of carboxyl and aldehyde groups that accompany the hemicelluloses removal. In the case of the oxidative treatment, the biosorption capacity was affected by the lignin content as well as the amount of introduced carboxyl groups. The best biosorption performance possesses jute fabric with 63.2 % lower lignin content as well as 81.1 % higher amount of carboxyl groups; biosorption capacity toward Ni
2+
, Cu
2+
, and Zn
2+
in monometallic solution is about 2.4; 2.2 and 3.5 times higher compared to the raw jute fabric, respectively. All jute fabrics exhibited the same affinity order (which is independent on the initial metal ion concentrations) toward heavy metal ions: Ni
2+
> Cu
2+
> Zn
2+
in the case of competitive biosorption. An increase in the initial metal ion concentration for two times in the polymetallic solution caused about a 35–59 % increase in the total uptake capacity of Ni
2+
, while the total uptake capacities of Cu
2+
and Zn
2+
increased for 19–38 % and 18–65 %, respectively.
Display omitted
•Effect of jute fabric chemical composition on the sorption and dielectric properties.•Hemicelluloses removal leads to higher moisture sorption.•Lignin removal notably increased AC ...specific electrical conductivity of the fabrics.
The jute woven fabric was treated with sodium hydroxide and sodium chlorite under different conditions in order to study the influence of the chemical composition on their sorption and dielectric properties. After the alkali treatments, the hemicelluloses content decreased in the range of 14.4–46.7%, which leads to elementary fiber liberalization and increased moisture sorption of the jute fabrics up to 15.5% and 11.9% at 30% and 80% relative humidity, respectively. The X-ray diffraction analysis shows that the removal of hemicelluloses for 14.4% and 36.6% was followed by a decrease in the crystallinity index for 3.0% and 18.8%, respectively. The additional decrease in hemicelluloses content of 46.7% was accompanied by a slight increase in the crystallinity index for about 14%. These results are in a good agreement with the results obtained for the AC specific electrical conductivity (at 30% and 80% relative humidity). After the oxidative treatments, the lignin content decreased in the range of 37.8%–79.0%, which causes two parallel effects: a slightly increased moisture sorption (up to 7.4% and 4.6% at 30% and 80% relative humidity, respectively) and crystallinity index (from 4.8%–16.6%). The jute fabrics with 37.8% and 63.2% lower lignin content and similar moisture sorption values have the same AC specific electrical conductivities at both relative humidities (30% and 80%) revealing a dominant effect of moisture sorption. The AC specific electrical conductivity of the investigated jute fabrics increases with increasing the frequency as well as relative air humidity, where the highest difference between the values of AC specific electrical conductivity is obtained at the highest frequency (140 kHz).
Woven jute fabric was treated with sodium hydroxide solution of different concentrations at room temperature, for different periods of time. After that, jute fabrics with gradually decreased content ...of hemicelluloses were obtained. The changes of the sorption properties (moisture sorption, water retention power and degree of fiber swelling) and dielectric properties (effective relative dielectric permeability, AC specific electrical conductivity and dielectric loss tangent) of alkali treated jute fabrics were investigated. After the alkali treatments, the degree of accessibility of the cell wall components to water vapor increased with increased severity of the alkali treatment. In parallel, the degree of fiber swelling and total water holding capacity of the fabrics were increased. The dielectric properties are very sensitive to fabric structural characteristics, chemical composition and its ability for moisture sorption. Thus, the obtained increase of the effective relative dielectric permeability after the alkali treatments can be attributed to the changes in the structural characteristics and decrease in the content of hemicelluloses, which further contributed to an increased ability for moisture sorption. The changes in the AC specific electrical conductivity can be explained by the fact that the hemicelluloses not only restrict the freedom of the water molecules to take part in the polarization process, they also change the structure in such a way that the mobility of the ions in the electric field is restricted. The values of dielectric loss tangent increased after the alkali treatments due to the increase in the number of polar groups.
Graphical abstract
Silicon photonics is a promising technology for addressing memory bandwidth limitations in future many-core processors. This article first introduces a new monolithic silicon-photonic technology, ...which uses a standard bulk CMOS process to reduce costs and improve energy efficiency, and then explores the logical and physical implications of leveraging this technology in processor-to-memory networks.
The RAMP project's goal is to enable the intensive, multidisciplinary innovation that the computing industry will need to tackle the problems of parallel processing. RAMP itself is an open-source, ...community-developed, FPGA-based emulator of parallel architectures. its design framework lets a large, collaborative community develop and contribute reusable, composable design modules. three complete designs - for transactional memory, distributed systems, and distributed-shared memory - demonstrate the platform's potential.
This paper presents new techniques to evaluate the energy and delay of flip-flop and latch designs and shows that no single existing design performs well across the wide range of operating regimes ...present in complex systems. We propose the use of a selection of flip-flop and latch designs, each tuned for different activation patterns and speed requirements. We illustrate our technique on a pipelined MIPS processor datapath running SPECint95 benchmarks, where we reduce total flip-flop and latch energy by over 60% without increasing cycle time.
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