Continuous and Real-Time Measurement of Plant Water Potential Using an AAO-Based Capacitive Humidity Sensor for Irrigation Control

Water potential measurement is an essential factor in determining water consumption management and recycling in the agricultural field. We report the development of a continuous water potential measurement system using sensors for water stress analysis in tomato plants with better irrigation plan feedback. The water potential sensor uses the capacitive sensing principle which measures humidity inside an anodic aluminum oxide (AAO) layer. An analog to digital converter with a wireless communication module system records the capacitance data of the sensing system. Calibration data of sensors derived from superabsorbent polymer (SP) and deionized water (DIW) mixtures can represent their water potential value. The method showed good matching of capacitance and water potential values above −7 MPa, matching the result obtained in tomato stem. The measurements were conducted for a few days with the sap flow and water potential sensors connected in series on a tomato stem. When sunlight is sufficient, sap flow increases; meanwhile, water potential decreases. The opposite phenomenon could be observed during the nighttime. With irrigation restricting conditions, both sap flow and water potential signal decrease, triggering the emergency watering signals. This continuous water potential sensing system can quantitatively monitor the plant stem’s water stress and set irrigation schedules to achieve high-quality products in the agricultural field

Colossal Absorption of Molecules Inside Single Terahertz Nanoantennas

Molecules have extremely small absorption cross sections in the terahertz range even under resonant conditions, which severely limit their detectability, often requiring tens of milligrams. We demonstrate that nanoantennas tailored for the terahertz range resolves the small molecular cross section problem. The extremely asymmetric electromagnetic environment inside the slot antenna, which finds the electric field being enhanced by thousand times with the magnetic field changed little, forces the molecular cross section to be enhanced by >10³ accompanied by a colossal absorption coefficient of ∼170 000 cm^–1. Tens of nanograms of small molecules such as 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and lactose drop-cast over an area of 10 mm², with only tens of femtograms of molecules inside the single nanoslot, can readily be detected. Our work enables terahertz sensing of chemical and biological molecules in ultrasmall quantities

The differences of resting connectivity between HAND group and nonHAND group.

<p>Upper images display the regions showing the FC with the left precuneus (P < .05, corrected). Lower images display the regions showing the FC with the right precuneus (P < .05, corrected).</p

Decreased resting state functional connectivity in nonHAND group compared to seronegative control.

<p>Decreased resting state functional connectivity in nonHAND group compared to seronegative control.</p

Impairment of domains of neurocognitive function.

<p>Impairment of domains of neurocognitive function.</p

Baseline characteristics of study participants.

<p>Baseline characteristics of study participants.</p

Renderd <i>t</i> maps of FC value.

<p>(A, B) show the FC maps of HAND with the seed located in the left and right precuneus, respectively. (C, D) show the FC maps of nonHAND group with the seed located in the left and right precuneus (P < .005, uncorrected).</p